Jump to content

Ex-Racer Spitfire Mk1 Rebuild


Recommended Posts

I can really relate to this. Having replaced the rear wings, sills, door skins and front wings on the mk3 Spit. 1/8" can visually make things look totally different. Door gaps to sills, front and rear wings, swage lines, to sill etc., and everything can move, or adjust, that sometimes makes it harder to get things right.  Really tricky. Waking up in the morning numerous times, thinking of ways to deal with loads of issues. Had to cheat here and there, adding and removing metal, on various edges. I had to be realistic, using repro panels etc.

What you've been creating is on another level.

I replaced the rear wing on my mk2 gt6 about ten years ago. I was suprised at the amount of lead that had been used at the factory to get an acceptable door to wing gap. Reminding myself of that puts things in perspective for me, that really skilled craftsman of the day with all brand new panels had to cheat with lead to get things to look right.

Edited by Mark
  • Like 2
Link to comment
Share on other sites

On 11/11/2023 at 6:29 PM, BiTurbo228 said:

Looking good! I guess every bit of work done on the form is some saved on the final product.

Also, just spotted that your green car had a 2.5l with a Sprint gearbox...and a Spitfire bonnet. I'm assuming it was set back quite far in the bay, and if so how did you sort the bellhousing clearance? I ended up doing a fair amount of clearancing, but curious if there's an easier way to get more space (e.g. lifting it up) as that would help a lot with getting a 2600 in there...

Simon, it's actually a GT6 Mk1 bonnet and the engine was only moved maybe 1/2" back. As a result there were only minimal chassis mods needed at the rear of the gearbox to get it all to fit when I put in the Sprint gearbox. Just lifted the body off to do the job as it was a lot quicker and easier that way to my mind, even just getting the various gearboxes in and out.

Chassis.jpg.483e0e6914741bed2fab75cc0bc2de66.jpg

  • Like 1
Link to comment
Share on other sites

Panic averted regarding the wings I think. Further investingation suggested that the problem was actually a bulge around the moulding for the bonnet catch.

Seems the pressing on the steel bonnet was a bit raised here and I missed it, annoying as it would have been seconds to correct on the steel panel. In the end I managed to sand down the area sufficiently on the GRP without completely eliminating the depression for the catch.

Things now seem to be lining up properly. Lots of filling and rubbing down today but it does seem to be coming up to a decent shape.

20231114_194906r.thumb.jpg.0c7d7d0e83a5887da324b7271d933943.jpg

  • Like 2
Link to comment
Share on other sites

  • 1 month later...

Bit weary of the sanding and filling and as a result been long pauses between working on the bonnet but practice on the drivers side has made the passenger side significantly more straightforward to get to this point.

20240104_171352.thumb.jpg.de9d6f33efcecb0125a52662216cd9ad.jpg

Almost at the point now where I've done as much as I can working by feel and I need to get some primer on to give a finish where I can see the lines properly and address the smaller imperfections.

So ordered some 2K high build primer which arrived today. It's black to give the best contrast. Becuase it's 2K cyano I'm going to be applying outside and it's not the ideal time of year so got the extra fast hardner which is rated for -5 to +15C. Although I'm hoping I can get something above freezing to apply it.

20240104_171428.thumb.jpg.4a4e3dc9e45902307d26e03caedf7a19.jpg

But before that the bonnet needs to come off for a final bit of fettling to the rear edge of the wings to get the door and sill gaps even now I have them measured. And finish off and fit the grille panel.

  • Like 4
Link to comment
Share on other sites

  • 2 weeks later...

Restoring the seam lines around the bonnet quarter panel. Started off with the straight seamlines at the wing join as a trial. Tried using the Dremel with a round tip cutter and the guard/standoff. A strip of aluminum as a guide stuck to the bonnet with double sided tape.

20240114_161939.thumb.jpg.21f5a95abede8e06b43ee846ea389e32.jpg

Did the left side first. Awkward on the vertical but went OK. Didn't go very deep and finished off with a needle file once there was a solid line fron the Dremel. The other side took me three attempts to get right!

Took a pattern off the steel bonnet for the top panel join. It's all curves which I guess makes sense on a double curvature panel. The inner line is the seam line, the outer one is for the offset for the Dremel guide. I'll make the guide out of aluminium again and at least I only need one as I can flip it over for the other side.

20240114_154808.thumb.jpg.93ad3b21936e557d17c6e45c44fd4b8c.jpg

Decided to leave cutting the grooves until after I've primed and finished surfacing the bonnet!

And I see that complete steel Mk1/2 bonnets are available again!!

Edited by Escadrille Ecosse
  • Like 2
Link to comment
Share on other sites

Meant to congratulate you on your attention to details, re-instating the seam lines.

A local friend is now well on with a Mk3 GT6 resto-mod.  A reasonably standard Mk3 roto with a 2.5 PI engine, complete with PI. And a GRP bonnet.  From Honeybourne.  You can probably guess how well that fitted!  It was HORRIBLE.  He even sent it back a couple of times for fettling.  It's now a very good fit, even by steel bonnet standards, though he's created some clever guides and catches to keep it honest around the bulkhead/door area.  Pretty sure he didn't put the seam lines back in though. :goodjob:

Link to comment
Share on other sites

  • 2 weeks later...
On 1/15/2024 at 10:46 PM, Nick Jones said:

It's now a very good fit, even by steel bonnet standards, though he's created some clever guides and catches to keep it honest around the bulkhead/door area.

Glad to hear it turned out well in the end!

Some meaningful progress with mine I think. Got the shape good as I could without getting some paint on it. So after measuring up what I needed to cut back and build up to get the gaps at the door and sills it was a case of lifting the thing off again for access.

With all the filler it is a lot heavier and all a bit marginal for a single man lift. Basically at 65kg and full reach to hold the thing I am at the limit of the overturning moment! Any heavier and my feet will come off the ground before I can lift the bonnet :blink:

Adjusting for the sill gap. marked up with a datum line. Material off at the back and on at the front. The other side was the opposite way round. On at the back and off at the front...!

I used gelcoat rather than filler to get a tougher edge.

20240116_094001.thumb.jpg.9dee5f4ba2ebdc0e40d30a5e4b8469d8.jpg

Trimmed back the edge at the door gap. See where a lot of the additional weight has come from

20240118_154035.thumb.jpg.aa7aa69072417d4db688a87aac7b88b2.jpg

Then back on the car for a final check of the fits. The lower corners need pulling in a few mm on each side but I'll get that with the bonnet off the car. Looks almost like it's supposed to fit now

20240122_100233.thumb.jpg.4304f4b4a549b6bc88690d88c55417a1.jpg

The rear edge of the bonnet is still quite flexible at the scuttle so now it's filled to match I stuck on another temproary brace to keep it's shape until I can add more internal bracing. And then time to get the whole lot off the car for the last time (hopefully).

20240123_180122.thumb.jpg.eb106b152dc1128e871cdb4be8ab60ea.jpg

That turned out to be the final straw weight wise and I couldn't get enough leverage to pick the thing up. Needed to add a couple of hookes in the ceiling and cross-haul the bonnet off with ropes.

Also finished off the grille panel. Which included a lot of filler on the lower edge to get it both straight and level to the rest of the bonnet lower edges. Easiest thing was to splodge a whole load of filler on and plonk the panel down on a flat surface. A few pinholes but otherwise worked well.

20240122_201513.thumb.jpg.fad46c3f99ed577cb53be3435459ad6b.jpg

Other way up...

20240123_171227.thumb.jpg.a1f1fc3040dec0966d575414888d8e4b.jpg

And trial fit in the front of the bonnet. It'll get glued in before everything gets a coat of filler primer.

20240124_165921.thumb.jpg.a73f1bc9e907f0529fd63e21d2400dae.jpg

And lastly glue in the reinforcement along the rear edge... Cross panel first then I'll do the side pieces at the same time as adjusting the corner inwards.

20240124_180224.thumb.jpg.09e998378eecf999f2c9ff4ca0fd8fcb.jpg

 

 

Edited by Nick Jones
remove dead picture links
Link to comment
Share on other sites

10 hours ago, Nick Jones said:

Can only see the last pic for some reason….:confused:

Thanks Nick.

Not sure what went awry but I have reloaded the pics although there are still dead image links I can't get rid of.

Edit: Thanks.  Now tidied up to remove the links (not sure why you couldn't) so hopefully it's now as you first intended.

It's coming on nicely but, wow!  So. Much. Work!  And this is the buck.  Though obviously this really has to be right for the whole enterprise to be worth it.  Hopefully the next stages are bit more straightforward and less time-consuming?

Link to comment
Share on other sites

10 hours ago, Escadrille Ecosse said:

Edit: Thanks.  Now tidied up to remove the links (not sure why you couldn't) so hopefully it's now as you first intended.

It's coming on nicely but, wow!  So. Much. Work!  And this is the buck.  Though obviously this really has to be right for the whole enterprise to be worth it.  Hopefully the next stages are bit more straightforward and less time-consuming?

Thanks very much for that Nick.

Yeah, the rather daunting amount of work in this bit should hopefully make the rather daunting cost (and anxiety) of the next bit worth it :blink:

The thing exercising my brain at the moment is just exactly how and where to place the splits and flanges for the final mould.

Link to comment
Share on other sites

Weather forecast for today was dry, sunny and windless. So a major push Sunday and yesterday to get all the last odds and ends tidied up on the bonnet so I could get the filler primer on. It's 2k primer so outside only for this.

First thing the forecast was bang on, frosty but sunny and warming up. And then the drizzle started FFS!!!

However by lunchtime it cleared and I got everything out and set to go. The primer is pretty thick and my poor little 2hp compressor had a big job on its hands - but did the trick.

Mixed up about 0.6 of a litre of paint with extra fast hardener to cope with it being cold. Ended up being about 7 degrees and the primer was just starting to kick off in the gun as I tried to get the last of it onto the bonnet which meant a few rough spots not flowing in too well but that's not really an issue.

20240130_160433.thumb.jpg.02f31640c87951faffd3bc20fc44c5e2.jpg

Pretty pleased with how it turned out. And now I can get a better look at the overall shape I'm quite pleased I seem to have got the filler done pretty well. There is one area at the rear of the left crease line on the top panel where it's obvious now that I haven't got the line quite right and I'm going to need to add a bit more filler. But given how much work that area needed I'm pretty happy.

I also think I have a decent plan on how to make the mould and the split lines. And also how to support everything while I make the mould. And as I need to turn the whole lot over while making the mould, how to do that.

Meanwhile however it's goign to be back to rubbing down as soon as this lot has cured properly.

  • Like 3
Link to comment
Share on other sites

Working round the bonnet rubbing down the filler primer.

Putting it on thick has done the trick and most of the minor imperfections have come out in the primer. Dry rubbing it down with 240 and 320 velcro backed sanding strips whic are generating a huge amount of black sanding dust (thank goodness for the vac system) but so far I am pleasantly surprised how things are going on the whole.

Fettling the wing seam 'finishers' to get an even height all the way along as they were a little high at each end. Also 'adjusting' the ends so they all stop about 1/8" from the ends of the bonnet as this will make moulding easier.

A couple of residual low areas that can be seen more clearly with a uniform coat of primer needing dealt with too. The one on the left (far) side needs most work, on the flat and rising surfaces. Pity I didn't spot this on the steel bonnet as it would have taken a lot less work to sort there!

Unfortunately with the primer on I can see that the detail round the side and indicator lights is still way off even after all the work already done so I thinking of plan B for those.

20240205_123824.thumb.jpg.f1e6f7e71b006c08ac7f0b9ec5c0b981.jpg

20240206_180026.thumb.jpg.c3fc454e0708df596fe9084b3418710e.jpg

Edited by Escadrille Ecosse
  • Like 1
Link to comment
Share on other sites

  • 2 weeks later...

@RedRooster I'll think about that!

Progressing with the bonnet and nearly ready for more primer. Except for the quarter light and indicator area which are not at all great. So unfortunately Plan B gets rolled out.

I was concerned about this area when I first looked at it and did consider taking a mould off the old blue bonnet to make repair sections I could insert. But given the condition of the blue bonnet I thought it would be a lot less work to fettle the part off the steel one.

So instead I get to do both. Hey ho!

This was the side that got smacked by the tyre wall after removeing the worst of the loose bits and sitcking the splits back together. Not very pretty and still masses of stress cracks (not that they matter too much for taking a mould.

20240211_172606.thumb.jpg.3a08a53c3e0cf1d30ae2e9a397f7d1bf.jpg

The two sides cleaned up and filled

20240213_143054.thumb.jpg.e4d9d1a11a4efc0f17309a0ae7b9b577.jpg

20240213_143118.thumb.jpg.5d2f624b1affa334cb21bdca3f3b46f8.jpg

Ready to take moulds

20240214_173817.thumb.jpg.b572ca68eeb72999136ded67f192637c.jpg

Quite a bit of coulour carry over from the cellulose even through the release wax

20240215_101526.thumb.jpg.0e5c601b794ded54b1038b179f73d943.jpg

But all buffed out fine and ready for waxing. Stoner release wax. From California, where else.

Hopefully get the panels made over the weekend.

20240215_162732.thumb.jpg.c909b01082706527ba913e95cd8e1566.jpg

 

 

  • Like 2
Link to comment
Share on other sites

  • 1 month later...

Bit more done on the bonnet. LHS has needed a bit more work than the RHS. Basic shape was generally better but the access on the car wasn’t easy due to the hoist so final finish not as good. And the rear corner of the top panel has needed a lot of fettling on the left side too.

Also discovered that the wing shape round the headlight was a bit flattened. Easiest solution was to stick on an appropriately shaped bit of aluminium as a template for the filler.
20240223_151110.jpg

20240223_152340.thumb.jpg.8ecf9dced13d529122a466dd92abd7f1.jpg

About 3mm thick at worst point.

20240313_172202.thumb.jpg.4d2bcbf627874d6b18dc8bb4f07ca91e.jpg

Then it was time to let in the side/indicator light sections copied from the old blue bonnet. Would definitely been easier to do this a while ago but that's hindsight.

Minimum amount of cutting

20240318_170142.thumb.jpg.867291425af430fd8fcca79ed2fea1ee.jpg

Patch trimmed to fit as best as possible.

20240319_155117.thumb.jpg.3f401d141a167eb8c8df1ae6ca7d1832.jpg

Glued some locating blocks into the bonnet then epoxied in the repair section. Once that's cured I'll add some GRP on the back to strengthen and make sure it stays in place as there's a bit of tension in there now.

Needed screwing into place as the replacement panels have a slightly greater spanwise 'twist' than the bonnet. In this case I think that the steel bonnet has a better shape as the blue GRP bonnet looks a bit 'flatter' along the bottom edge as if it had a dunt before they took the mould.

Other side to do tomorrow and a bit of filling then if there is a bit of decent weather I can get another coat of primer on.

20240319_172909.jpg

 

  • Like 2
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...