Bonnet done

 Productive day today, even though it was only a few hours. The bonnet support has been welded up and fitted;

It's easier to see with the lid down;

It wasn't too bad, the verticals were just 'straight up', then I needed three cuts in the horizontal portion to create enough of a curve to fit under the bonnet. I had to profile the ends to cope with the start of the curves, but that was fairly easy.

But... I think there is a bigger issue. That picture from under the bonnet was not difficult to take, I should  have had to get a lot lower. And the support is awfully tall. Now, it is tall at the moment, and the horizontal bar is only tack welded. Once I have the body at the right height, I can adjust this to match. B

It's still high though. This is a pic from the drivers position;

I am basically looking edge on to the bonnet. If this was the car, only my forehead could be seen above the bonnet. 

There's a few things here though. This edge is on top of the side outriggers, not underneath. The bonnet also hooks under the body as well, so that's at least 40mm drop already. Then the seats have the rails, foam and cover. So potentially there is a good 100mm to go for my viewing angle. And strictly speaking only my head needs to be above the chassis. As a last resort I could drop the side outriggers below the chassis, but I don't really want to do that. Actually, as I think about it, the body is at the correct height, so dropping the outriggers won't be needed. 

As with every job I 'finish', this one isn't quite done. But it's only the bonnet pins and trimming it to match the body, so I'll count that as complete.

Time to think about the next job. Actually, a small job that'll be pretty easy to finish now, the radiator and fan mounting. Just a few tabs to weld on to the newly provisioned bonnet hinge, and job done. 

Change of plan (again!)

I have been recently watching the 'tools n track' Youtube videos where they build a 7. They've been quite amusing, mainly because they have hit many of the issues I have found, as well as some others. Unfortunately they've already cost me £200, the video I watched last night kindly reminded me that I've not serviced the engine at all. If nothing else, everything is ten years old without being run so just on age things will need replacing. So I have a cam belt kit, spark plug leads, filters, gaskets and all stuff coming from MX5 parts. 

Oh, and a few exhaust parts, but I'll come to that in a few posts time... :)

One of the other videos I watched last night was around the body tub. I didn't think this was going to apply to me, but it raised a very good point. There is a curve in front of the rear wheel on an average seven, that matches with a curved piece of metal on the chassis. In the video the fibreglass tub has the curve but the metalwork isn't there to support it. And quite rightly, it's a place where you'd put your hand to support climbing into the car. 

It then occurred to me... I'd do the same getting in and out of my car. I'd use the body (possibly even sitting on it) to support the transition, but at the moment I'd be sitting on a nice brittle fibreglass tub. It might not break but it won't be pleasant to find out. So my plan of just filling in the sides is now more like 'build some structure into the sides'. Fortunately it is just a combination of planned tasks that I've not started.

First step, build a frame. This will be built around the bodywork, something like this;

(Hmm, that didn't come out as well as I had expected... )

The red line shows an outline for the frame, this is where the strength will be put in. I'll try and get it as close to the fibreglass as possible, to the point where I could use rivnuts to fix the body to the frame. While the red lines are straight lines, there's all sorts of curves going on there that I would like to match. 

A top view shows what I would have to deal with;

There seems to be more curves showing here than in the previous shot, so it is possible that some of them are just built up fibreglass. Anyhow, if I take it slow, and use 'lobster back' curves I should be able to follow the outline quite well. 

Just looking at those photos though, I may need to rethink my plan of getting it tight to the outline. Fibreglass doesn't have nice neat corners, even with fairly sharp right angles on the outside I'm not sure I can get that close on the inside. And on the dashboard edge there is no real benefit to being so close to the dash as that is already pretty strong. Perhaps going back to the original position to build up support were it will be cut is going to be better. Well, inline with the chassis is the most logical position. 

And then there is fixing... using Sikaflex to fix this frame to the body makes sense, then use some semi-permanent fixings to bolt it to the chassis? 

I have my first job though, build that frame. Fixing it to the body and chassis can come later. As this is a chunk of work I might put the chassis on it's side for a while, then the body can be brought back into the garage and serve as a template. 

Other half of the bonnet

 This started off so well, I managed to get a piece of wood out of my stash, cut it to size and do the profile. That's when I came unstuck...

The bonnet is a very different profile to the main body. While the body is a standard curve, the 'shoulders' of the bonnet start very early on before they head down to where the headlights are. Furthermore, the fake 'bonnet' has indentations that also make the curve a little more stubborn.

Putting the template on top of the bonnet shows the issue;

To be fair, it does follow the profile quite closely up to a point, but then the bonnet edge and the curve just make a mockery of the template.

However... this support has two main targets, support of the bonnet and the ability to install bonnet pins so it can be locked. Both can be achieved by simply making the support as wide as the fake bonnet. Actually no, that isn't correct. If I did that, I'd lose the scuttle panel space that this whole piece of work is meant to give me access to. 

OK, time for me to have a think about this... One thing I am going to do is at least cut that template to suit the chassis. While it is as wide as the body, the chassis isn't. So there's no point in keeping it wider than the car it's attaching to!!

As with everything on this build, my thoughts now turn to one of the other tasks I have, the sides of the cockpit;

The front is ok, that needs a scuttle panel which is partly covered by the work described above. The back also isn't too bad, yes it's a curve but it's only about six inches or so and can be simply filled in with whatever rear support I'm building up. 

The sides are then the challenge. Logic would suggest a panel going out from the chassis, meeting another panel coming down from the bodywork, would be the easiest option. Each half would be rivetted to the body and chassis respectively, with a right angle bracket and maybe rivnuts to join the two. 

There's a few issues with that. First it won't look particularly attractive. Second I'll be losing a lot of space for storage etc. On the other hand it would hide a multitude of sins where the IVA ball of terror wouldn't be able to check for projections. 

Time to make a decision on this... I'm going to leave it for now. Once the scuttle support and rear support are done, and the triangular bits at the rear have been cut out, I'll see what would be best. 

50% of a bonnet

 Yes ok, half a bonnet doesn't sound healthy, but it's actually a much better weekends worth of work than it sounds. I managed to get the bonnet outriggers and hinges welded up, so the front of the car is exactly where it needs to be.

It started with the bonnet side of things, a quick 'inverse pi' welded up to form the body of the hinge. Then a short piece of bar to form the inside of the hinge, and with a bolt through that gave me this;

I made up the inside of the hinge while still attached to a bar, so I could position it roughly where it will live. This is where it will attach to the chassis at the bottom (albeit with a slight faux pas I'll come on to shortly);

And this failed attempt at photography shows it clamped to a longer piece of metal and heading towards the chassis at the top;

This is a better view of the same, but from above;

A quick triangulation later, and I have upper and lower fixings to weld to the chassis;

Same from another angle;

Which leaves me with this gorgeous view;

Made even more gorgeous when I sit the radiator in between;

With the rad in place I can really visualise how it will split in three to match this car;

Anyhow, enough dreaming and salivating, I still have a lot to do. 

Firstly, the mistake. Although I'm not sure it was a mistake. Basically the bottom arms for the outriggers were outside of the chassis by about 10mm. I did think I could just adjust the angle and pick up the uprights, but by my reckoning that would have had bodywork loading in the centre of an unbraced bar, pretty much where the suspension wants to go anyway. So that was a no-no. I did check the measurements, but as you can see from the photos the radiator is pretty snug in there. It was a quick fix though, a bit of metal to bring the bottom bars out and square them up with the hinges and upper bars. 

So that is the front part of the bonnet, it works really well but needs a retaining strap to stop the bonnet tipping too far forward. If I let it settle under it's own weight it'll tear the hinge bar out of the fibreglass. A retaining strap shouldn't be difficult to make up though, as long as I don't open the bonnet in windy weather!

Next job is the back edge. This needs to have a frame built as I described in the last post. It also needs to match the body, and since the body is more rigid than the bonnet I thought I'd use that as the reference. 

So what I did was turn it upside down, mark a spirit level at regular intervals and measure vertically. This is the spirit level in action;

And this is the curve when I move the numbers into Excel and plot a graph;

The curve is a little exaggerated due to the X vs Y dimensions of the image, but it shows a fairly gentle curve. The next step will be to make it out of wood and use as a frame.

The sharp-eyed people may have noticed the numbers on the left. That is the distance from the top of the spirit level to the bodywork as seen in the picture above. But not all of that is to be made out of wood. First there is the spirit level itself at 50mm. Then the lip of fibreglass, lets say 5mm. Then the big jump is from the chassis bottom to the chassis top which is 353. That means that rather than going between 670 and 712 mm, it only goes from 262 to 304. Also I don't want to make the wood come all the way down to the chassis as I just want to capture the curve rather than the complete distance. That means that while the wood template needs to be 1350 long, it only needs to be maybe 150mm tall. Time to go rooting around in the garage.

Once the template is made I can then test it on the body and bonnet, then figure out how to convert it into metal. Not only that, it needs to have bonnet pins fitted to it for the bonnet, which need to be IVA friendly. Aerocatch come up as the main IVA friendly catches, but they're not locost at all. If I could DIY them with some threaded (or even solid) rod and a few washers/plates/etc then even better.

Bulkhead

 This weekend has been very productive already (even though the temperature in the UK has dropped like a stone!), I got the full body on and was able to see how the two halves lined up. Well, I say 'lined up', it's nowhere near lining up!! I knew that already though, the whole body is designed for a different chassis layout.

What it did show me was how far it overlaps, and it's looking really good from that point of view. I have to trim down the bonnet to bring it in line, but then I'll just need some edging trim to get it to fit with the body. 

It also means I can start work on the front hinge as I know where the bonnet needs to end up. But then something occurred to me;

This photo shows where the front of the body fits... right in the centre of the scuttle section! For reference, with the standard seven body the cockpit section finishes at the first crossmember. The part of the chassis in the photo is essentially part of the engine bay, and usually hosts the battery, coolant tank, that sort of thing. Here's an example from Skov's build;

As you can see, that's quite a bit of surface area that I don't currently have access to. So I need to regain that area.

As a secondary benefit, both the body and the bonnet need support at that position. The bonnet in particular needs the rear latches/fixings so it can close and lock. So I need to make a box essentially. The front of the box will be bounded by the chassis bar on the bottom, then continuing the sides of the chassis up to a cross member that will follow the profile of the bonnet. The rear of the box will be the same process, but coming up to the body at the top. 

Once I have the edges in place, I can then box it in so it isolates engine related things from person related things. That'll be the same as how Skov has it in the picture, but I'll end up with an extra hoop for bonnet support. 

It doesn't have to be overly pretty as it's more structural than decorative. However I do need to follow the curve of the body and the bonnet. And both need to be strong enough to keep things in place, as once it's in place I'll need to remove the rest of the material from the body. 

Ah, trimming the body... what a delightful job to look forward to! I want to keep at least some of the material in place, but maybe only an inch or so. Here's a few measurements I made of the front face;

Even retaining an inch below the recess I still need to trim nearly a foot of material, and recreate it further back in the car. Oh, and it needs to be adjustable... while I've taken a few measurements I still need the option of fine tuning, so there will need to be some movement somewhere. 

(Edit) Does it really need to be adjustable? The bonnet I think yes, I'd want some fine tuning in order to get it to fit well against the body. But I'm not so sure about the body itself. I think I'll get the bonnet one done first, because I can get the hinge sorted at the same time. Then get the chassis lowered, get the body on and work with that. 

And I also need to trim the rear of the body where there are triangular parts that come down the side of the chassis. They're in the wrong place in my car so are as useful as a chocolate teapot. I'll need to trim them and design a replacement profile that will fix to the car. Hmm, that is going to be a pain in the back side, it needs to be done with the body on but with the body on there isn't much space in the garage. Well, one step at a time. 

Front end

 Oh I do like the look for the front of the car...

It's the first time in a long time where I've seen the front end out of the shed, and while it's picked up a few scrapes and dents it still shows what it could be.

The main reason for getting it out though is to confirm the radiator position, and that seems to look fine;

Which it does quite nicely. It also gives me the opportunity to fill in the voids either side like I wanted to, following this style of car;

Obviously it's only going to be in the 'spirit' of how that car looks, but I think I can get it quite close. 

Next job is to get the outriggers and hinges sorted for the bonnet. And for that I need a wheel back on. 

(Edit) Oh, and this final picture does show that I'm about seventeen shades too light with my green!! No matter, I can sort that when I come to painting, at least having the green gelcoat as the undercoat will give me a fair chance of getting to that nice deep green colour. 

Radiator and next steps

 Today was meant to be figuring out how to fit the radiator. Well, technically it was, it's just that I didn't find a solution!

The problem is the pipes, they're both on the same side as well as the thermostat. Which means that whichever way I put it, at least one pipe is trying to flow water directly into the chassis or the suspension. 

I can see two options...

1. Mount the radiator offset. Just typing that makes me shudder, and having to look at it every day would be worse. If it had been in a seven it wouldn't have mattered so much as it's barely visible, but on the Healey bodywork the front is very exposed. So having it offset would be very obvious.

2. Mount the radiator vertically. I want to go for this option, mainly because it works, and all the pipes simply fit over the top of the chassis. My only reservation is whether it will work as a radiator when it's up that way. I'll see what the people at LCB say, but I think this is a much preferred option. What's more, the original Healey radiator was vertical so it would look better. And I could use some ducting either side to finish it off and increase air flow through the radiator. 

Tomorrows task will be to get the front of the car out of the shed and cleaned off so I can put it in place. This will serve several tasks, as well as getting the radiator confirmed in place I can do the outriggers, electrics and various other things. It's been long overdue, and no doubt I'll be evicting several thousand spiders and other creepy crawlies from their home. It'll be nice to see the front of the car again though...

Painting

 While I was painting my chassis, my mind did turn to painting the bodywork. When the body arrived I could see that the gelcoat wasn't perfect. After all, I'm not paying for an Ultima body so why should I expect Ultima quality? :)

Over the years the body has also had a few scrapes and dents so it needs a top coat. My previous attempt at painting my bike showed that while it came out ok, the smell was unbearable!!

I think part of it was using a spray gun, and to be honest the thought of  a nose full of paint for the next few weeks is just not nice!! So I'm going to go for a 'roll and tip' approach, like this video;

https://www.youtube.com/watch?v=k-SGcSlNmoo&ab_channel=EyeInHand

I like that the result is '90%' perfect and reflects the perceived age of the car. I had thought of going completely matt, but I think that would have turned it from a vintage car into an army reject!

In other news, the tank is now strapped in with rubber and steel straps;

The rubber does look a bit untidy though, so rather than have them sticking out as per my original plan, I'm going to trim them flush with the steel. 

The pedal box has also been securely fitted;

There is a tiny amount of flex at the top of the black section, but whether that translates into a spongy brake pedal I have no idea until I'm in the car and facing that previously mentioned 'oh sh*t' moment on the road. But with five 8.8 M6 screws, of which 2 go through the chassis frame, I'm happy it's as good as it can get without fully welding it. 

Oh, and there is an extra bolt fixing for the brake bias valve, previously it was just a self tapper into the frame to keep it in position but now that's also got an M6 through bolt.

Radiator mounts next, then I want to flip the chassis and make sure I didn't miss anything while painting. I also want to paint the seat frames to ensure they don't go rusty.  

Another long pause

 And just like that I've gone from July to October with no updates. That is quite impressive! Unfortunately it was due to another bedroom being redecorated, so the car had to be pushed to the side of the garage while I did various things with wood, plasterboard etc.

In any case, I got the car flat again last weekend, and I've been working through things during the week leading up to today. I wanted to get the chassis completely finished, and now it is;

Everything looks so much better now the tube ends have been capped and everything has had a layer of primer. The bottom of the car is still missing some paint, but most of that needs to stay bare for the flooring to be glued in place.

Once this has dried, I can get the rubber straps glued on to the fuel tank frame. I've trialled it with superglue and it's a really strong bond so I'm optimistic it'll be an easy job. Then I need to drill the holes for the fixing screws and that is the fuel tank done. 

Oh, and the engine mounts are now complete. An extra plate was welded on to the frame at the front, then an M10 hole drilled through the engine mount and the plate. They should bolt up nicely when the engine is to be properly installed. I do need to drill the gearbox mount though, I think I have positional photos to know where the hole goes.

Aside from that, I did have a plan to make some decent progress recently. My contract ended and I faced a bit of time with no job. Time that I was going to spend getting a load of stuff finished on the car. Fortunately for me a new job came up within a week, so that is keeping me busy. Maybe when this job finishes I might get some free time. 

Next few jobs;

1. Rubber for the fuel tank and fit the tank. Should be easy now the paint is done.

2. Put some threads into the pedal box fixings. The holes are there but they are purely decorative at the moment. I need to make them functional either for a nut and bolt combination or for a threaded hole. Either way will work as they don't have to be really strong. Their biggest challenge is for those 'oh s**t' moments when I'm pressing hard on the brake pedal. 

3. Radiator mountings need to be welded in place. Just a few brackets, nothing challenging.

4. Stock take nuts and bolts. Well, specifically bolts. I'm aware that during my work some of the bolts have been repurposed, damaged or are just too short for the job. I need to go through what I have against what I need, and order the difference. The main challenges are the long bolts for the rear suspension, while I remember getting some appropriate bolts I can't remember whether they were ok... or even where they are! 

5. Seats need to be upholstered.

6. Body on so the electrics can be added. 

Onwards and upwards...

Emissions test

 Another post for IVA, the engine number. I've had the letter from Mazda confirming the age of the car, as well as confirming the engine is the original fit. But the engine number is in a really unpleasant place and is extremely difficult to read, so I thought a picture of it might be good. 

I'm kind of taking a risk on the internet, there may be people that copy that engine number for their own purposes. But at least if I can show a physical stamp as it is then the emissions test might be easier.

I also have a VIN that needs to be stamped on the chassis, obviously I'm not going to post that on the internet as it needs to be plainly visible by default.

Fuel tank straps and seatbelt fixings

 First off, a disclaimer... I was having a nightmare day of welding, so some of them aren't pretty! But they're photographed here for IVA inspection, so bear with me.

First the fuel tank straps;

This the side view of the tank, with a tag going downwards which will bolt to the frame. The bottom section will be welded to the frame along with the back, then the top left corner will be another bolt. I have some rubber strip on order to mount the tank with, as soon as that arrives I can finish the sizing to ensure the tank is secure.

Next, the seat belt mountings. These had planned to be full brackets, but actually the location where I want the seat belts mounting is already partly taken up by the rear diff cage plate. So what I did was cut 3mm plate and fill in the gap;

As I mentioned, really not pretty welding but it was a very tight corner. They both got good penetration though, and with them welded on three sides they're about as strong as they can get for the seat belts. I need to flatten the other side in order for the aluminium panel to sit correctly. 

The last little job from this weekend was to finish welding the roll bars. And that is where this happened;

High wire speeds, high temperature and too close with the shroud was just a bad combination, this is the aftermath of the shroud getting welded to the pool! I've got some die grinding bits on the way, I'm  going to cut this away and have a look. If it looks to have penetrated then I'll just make it pretty, if not I'll remove and reweld. 

Next job will be to do the seatbelt fixings on the roll bar cross support, they'll be for the shoulder brackets. They're all cut but then need to be positioned so that the belt doesn't catch on metal. 

One job I did forget was ordering the prop shaft. I had got the measurements from last time I put the engine in place, I need to get some prices and get it ordered. I still don't know whether new or recon is the best, it's not just a price difference. 

Cooling

 To tick off one of the jobs, I decided to have a look at cooling. The donor radiator is just too large, I needed something half the size. The book recommends a VW Polo radiator, and going back to 1996 I can see one that would fit quite nicely. 

The problem comes from plumbing it in. The MX5 cooling system is fairly straightforward;

One loop for the radiator, one for thermostat bypass, and one for heater. The bypass one can stay where it is, the heater one will be looped back. That leaves two pipes to get from the engine to the radiator.

But then I need a reservoir connection, and this is where it gets messy. The MX5 reservoir isn't pressurised, it's cap is just a 'lid'. The coolant pressure is controlled by the radiator cap, which has a tee off to the reservoir. Therefore it only gets water into the reservoir when the pressure is too high. The fill is done through the cap. 

The Polo radiator doesn't do that, it uses a pressurised expansion tank;

The system is filled by the tank, and the tank cap is a pressure release valve. 

All of that means that if I use the Mazda reservoir, it'll end up being under pressure rather than just dealing with the overflow. The lid won't stay closed, water will go everywhere, game over. I think I need to move to an expansion tank like on the polo. But then the plumbing gets challenging, because there is no tap for an expansion tank. 

Following the Polo cooling route, the filler is connected to one of the lower pipes, and the overflow to the top. It kind of makes sense, and hopefully I can do the same. I have found these connectors as well;

https://www.carbuilder.com/uk/black-nylon-stepped-t-piece-3228mm-1512mm

Which I suspect may come in very useful. If I use a T piece to join the heater pipes, then connect the tank to those pipes, that should deal with the fill. The overflow can then connect to a higher pipe. 

What I do need to do is get to a scrapyard and find an expansion tank. Thankfully the expansion tanks were used for pretty much every VAG car so it won't be difficult to find one. I just want to find one that isn't really big and bulky. 

I'll also do a bit of Googling to see what other MX5 based Haynes have done, they must have ended up in this situation as well. 

(Edit)

Skov to the rescue again! Through my build I have frequently referenced his build, even to the point where I use the same blogger.com host. In case I lose the bookmark, here is his blog;

https://mx5-haynes-roadster.blogspot.com/

It's actually completely done, his last post was a farewell as the car got sold. So sad... :(

Anyhow, as expected he's done pretty much what I'm doing, using Polo donor parts. Here I can see pictures of the Polo expansion tank;

https://mx5-haynes-roadster.blogspot.com/2012/09/cooling-system.html

Along with clear photos of how/where it's plumbed in. He has done exactly what I am planning to do, plumb it in at the rear of the engine on the heater pipes. The only difference is that his radiator does have the extra connection back to the expansion tank. I'll need to plumb that in with a T piece off the upper radiator hose. 

To do list June 2023

 I've had a look and it had been three years since this list was first done, Covid had a lot to answer for but I'm hoping to catch up again now. So here's the list with comments;

• Finish off BR10 cut. It's just a raw end from where I had to cut it off to fit the engine, I need to smooth and cap it. Still to be capped, but as with the next one I want to go all over the chassis and finish it. Even working on the back end I found two other tubes open that need capping. 
• Other weld finishing. Just a quick sanity check once the chassis is open. To be done.
• Handbrake mount. I still want to put it under the steering wheel, I like the idea of it being hidden but I've no idea how to do it! I know where it's going and it's already been tested, it won't be under the steering wheel but it will be tucked away.
• Gas pedal mounting and linkage. Done, but....
• Clutch and brake pedal limit stops. All three pedals need limit stops in both directions.
• Seat belt reel mounting. I figured they should be mounted in the inside but they still need to meet all three points without touching the car seat. Yep, I know where it's all going so I can weld up the brackets required. 
• Radiator mount. I don't actually have a radiator yet so that might be a delayed job. Ah, I still need a radiator. Best go shopping, or at least go junkyard hunting. A quick Google suggests 310-350 tall, and 435-465 wide. I need to measure the MX5 fan cowl though, I would prefer it to match that if possible. 
• Roll cage. Still not sure what I'm doing here. 99% done. 
• Exhaust. This will be after the bodywork fitting. This will be a big job, but the engine isn't in yet.
• Oh yeah, bodywork fitting. This needs to include;
• Outriggers on the chassis. Side ones done, rear to be done.
• Mount points on the chassis. I think just the front and rear lips, but it does require curves. 
• Hinges for the front section. Yep, to be done. 
• Trimming the panels to suit. Mainly from the top of the chassis sides to the side of the body tub. I'm thinking aluminium rivetted to the tub and screwed to the chassis. 
• Painting the chassis once completed. Long way off for this one!
• Propshaft resize. I think it needs shortening, but I can't measure it without the diff and engine being in place. It does need shortening, but engine in place is needed first. 
• Fuel tank mounting brackets and straps. Strap metal is waiting in the garage to be bent into shape.
• Fuel lines. Ah yes, I need to buy a few metres.
• Scuttle panel. Interesting, I'd not really thought about this. Perhaps something to consider when the tub is in position on it's brackets.
• Windscreen (maybe? Not yet though). Nope, not for IVA. 
• Brake pipes (solid and flexi). Done and done.
• Wiring loom. OK, I've put it off for so long, but I think that is the next big job. Stripped and taped up, no idea whether it'll work though!!
• Dashboard and battery mount. That's a couple of interesting ones, again probably more for when the bodywork is in place.
• Drive it away. Yeah whatever!!

I think engine install has got to be the next big job, closely followed by the bodywork and then the front end fitting with hinges. Oh, and shopping list for lights!

Bad and good roll hoop supports

 Time for the last update from the weekend. First the bad;

This is probably the first time I've had porous welds. I did initially think gas problems, but now I've had more time I reckon it was thread cutting oil. The caps had been tapped just prior to welding, and the oil must have still been present in the seam. It's a little bit coincidental that the bubbles are roughly where the seam is, and only in particular points on the circumference.

The only thing to do is grind it all away and reweld. Which I did, and to be honest I was much happier with the penetration from the second weld. One was even good enough to keep as is, but because the other one needed tidying I thought I'd do both.

This is the final result, two capped hoop supports with their rose joints and weldable brackets ready to go. Obviously this is upside down, the brackets weld on to the hoop like this;

I'm really happy with the outcome, once they're fully welded and the bottom part is also fixed to the plate it's going to be very rigid. I guess I won't know the ultimate strength without something nasty happening, but at least this is done as well as it can be.

Last job for this then, cut the second bar and fully weld both, then brace down to the bottom of the diff cage. After that it'll be a bridge out to the bodywork at the back. 

Boot positioning

 One thing that occurred to me was that the boot lid is a separate piece, so in theory I could check it's location and see what would need to be cut. As I took it out of the shed I could clearly see it was wider than the support tubes, so at first glance it suggested I would need to cut the boot lid (or even have it non-functional). But then I went back to old photos;

This shows that the fuel tank is just short of the boot lid (actually this picture is prior to the platform being made so the boot lid and fuel tank most likely line up). So I had a go at putting the boot lid in the correct position;

It turns out that while the width is clearly enough to interfere with the support tubes, the distance rearwards is enough to ensure the support tubes are going through bodywork and not the boot. That is further confirmed by the bodywork length being 18 inches from behind the seats to the boot lid. Checking that against the positioning of the boot lid suggests it's 'about right'.

My only concern now is that the bodywork may actually line up exactly with the cross bar on the roll hoop. So instead of simply cutting a couple of notches out of the bodywork, I may have to take an entire section out. Of course, that might mean that the cross bar also serves as a terminator and a support for the rear section, then I'll just need to add some trim between the bar and the chassis. Hmm, that actually might work out better, I had been wondering what to do with that rear lip. 

Rose joint caps complete

 After a lot of welding, cutting, grinding and more welding, I finally have my rose joint caps. Two layers of 5mm steel with a welded 12mm nut on the back, giving 22mm of fully threaded end;

A quick check against M12 bolts shows everything looking good;

And here they are in place on the tubes, with the rose joint screwed in and the hoop mounting brackets ready to go (more 5mm steel);

I'm happy with the work, it all went to plan and while it probably won't pass MSUK inspection I can see enough metal at every stage to ensure that it will help if the worst happens. The next stage is to cut the bars to length and weld the fixing plates in place.

Talking of welding, I went back over the cross bar on the roll hoop and fully welded it;

Unfortunately, while I was happy with the weld itself (reasonably tidy and with good penetration), it did pull the hoop in and stopped the fixings from matching the holes. I had expected it when welding the hoop itself, so I guess it was just a delay to the inevitable. I needed to slot around 3mm into each of the eight holes to cover the shrinkage, so now the fixings have washers underneath them. It's still as strong as before, the washers are 'belt and braces' so to speak.

Now comes a little frustrating bit. I wanted to look at how the tank was going to be strapped in, compared to the support bar mounting plates. I managed to get it wrong;

The fuel tank sits on top of the plates on both sides. This means that once the tank is strapped down, those plates will not be as easy to work with. Particularly when I'm inside the boot of the car trying to wrangle the support tubes into position, I don't want to have to fight the fuel tank as well!!

Of course, it's a fairly easy fix here, I just need to trim the plates a bit. I do have the trailing edge that is already shorter, and rotating the plate showed that it would work. It's just one extra job.

I've also remembered to fully weld the bodywork mounting on the drivers side, so that's now ready to go. I think for next weekend I'm going to get hold of some Sikaflex and get the bodywork in place. So before then I need the support bars finished. 

I also want to get the straps sorted for the tank. For some reason I thought the fuel tank straps were going to be soft, turns out the book asks for 2mm steel. Of course, I don't have 2mm steel, and definitely not in the length required. B&Q have it, and while it seems to be a bit expensive it appears to be the 'normal price' for steel now. I knew I should have got this finished a while back, all these little bits are going to end up costing more than most of the chassis. The tank also needs insulating from the rest of the chassis, so I need to find a rubber strip of some kind. 

The next post will be having a look at the next jobs, or more importantly the next purchases. There's not much left now, it'll be on to engine and body work. It's looking to be a nice summer (fingers crossed) so that will make things easier to bring things out of the garage to work on. Of course, we have thunderstorms predicted for today, so just indoor stuff for now.

Rose joint install

 For the roll bar supports, the rose joint mounting is going to be crucial. It would be ideal if it was fully threaded, but I've got no way of turning a suitable insert. So I want to get as close as possible with the options I have to hand.

What I've decided on is an M12 nut, mounted on the back of a 5mm plate that will be welded just inside the tube. I will then have a second 5mm plate welded to the end of the tube. That gives me about 20mm total threaded surface, with an end plate that is double the thickness of the tube itself. The rose joint is then inserted along with a lock nut. 

The only problem with that design will be the multiple layers and how the thread will work between them. Ideally I need to weld up the three layers away from the tube, then cut the thread. That will allow me to match the thread on the nut. If I do that I'll be installing a 'top hat' into the end of the tube and only having one weld to the tube. It also means the weld between the plates will most likely need grinding away as well, again for the top hat design.

What I'd prefer to do is weld the nut to the smaller plate, cut the thread on the smaller plate, weld that into the tube, then weld the larger plate on top. But while I could cut the thread on the smaller plate, I couldn't do anything with the larger plate. 

Thinking about it, the best option would be to weld the large plate on then tap from the other side. I'll have to do a bit of work on that one to see if I can get the tap all the way through the tube, initial thoughts would be to fix the tap into a socket then use extension bars (or even a length of steel) to get the tap all the way along the tube. I might try that step first to see if it's viable. 

(later that day...)

I think I'm overcomplicating things. I screwed two spare pieces of metal on to the joint along with the bottom and top nuts. It left me with about two threads spare so I think it's perfect for the end cap. But I am going to do the whole thing off the tube first, weld all the layers together then tap straight through. As long as I get the holes in line then it'll be the strongest way of making the cap, then having only one weld to the tube will be less of an issue. 

So it'll be a fixing plate that is twice the thickness of the tube, and a total thread length twice the thickness of the joint. Then it'll need welding to the roll bar hoop, that should be pretty easy. I suspect 3mm plate will be best here, fully welded of course.