Bodywork Update

It seems I've posted nothing for ages. I've hardly even taken advantage of the ghastly lock down, but I have done one or two things worth posting up. Mostly I've continued doing the bodywork.

First off, I started renovating the front wheel arches. They were in a pretty poor state and it was really touch and go as to whether I would junk them and just get new ones or fix them. I decided to fix them, but I still might just get new ones later. Its been that kind of year!

This is what they looked like to start with:

This is just the drivers side, but the passenger side was as bad. There was a poor repair where it looked like tyres had rubbed through, large sections of the reinforcing were blackened and split, the front edge was frayed and naturally, both were covered in star cracks. The bad patch was easy to grind off and repair, so I did that first. Next, I tackled the reinforcing that runs around the free edge. 

This looks like it's made of glassed over pith-wood sections. I imagine this provided support for the reinforcing lay-up, without adding weight. It seems that when the wheel arch had flexed it had cracked the reinforcing, then water had got in and the pith wood had rotted. When I ground out the bad reinforcing sections, the wood had turned to black dust! 

I couldn't locate a source of the wood in the sizes I needed, but  I found that lengths of rope would do, if I stacked them, two on the bottom and one on top, and then laid mat over the top. I glued them down with contact adhesive to keep them in place while I glassed over them.

I also repaired all the cutouts for the suspension so that I was left with a blank wheel arch to re-cut when I began re assembly. This one is tissued.

Another reason for keeping these arches was to use them as trial pieces for practicing re tissuing. Why? well, because after months of rubbing down and repairing the shell, I was still finding sneaky little  cracks and other issues with the gel coat and I was coming round to the idea that the only way I could be sure that rogue cracks don't reappear after the paint stage and ruin the job, was to resurface the whole car. Eugh(!).

This is the approach used by many restorers of classic fibreglass cars, but there is very little information out there on the details of how to do it. Most of the information on repair, relates to boat hulls, but boats are not typically painted afterwards and they aren't typically resurfaced either. Anyhow, rather than relate my frustrating failures, its probably better to just bullet point the things I learned:

1. Don't expect re tissuing to smooth out any imperfections; it just adds hours of rubbing down. Rub down to a good shape first. If you are over tissuing smooth gel coat, rough it up first with 40 or 60 grit. New resin adheres poorly to old.

2. I used pigmented lay-up resin,  to see when I was rubbing through the tissue back to the original glass. I used white because:

3. A mist coat of black rattle-can paint is a great help in ensuring you get an even surface. Also it shows up well over the white pigment.

4. When laying down the tissue, I found that using a brush with a stippling action tended to leave an uneven surface and occasionally rucked up the tissue, which is difficult to reposition when wet. Using a gentle "painting" action is an improvement, but using a solvent proof mini roller was a vast improvement in surface quality. There is a danger that the lay up is drier than with a brush though, so you need to be careful to use enough resin to wet out properly. You will probably have to stick to brushes on the complex shapes.

5. Try to minimise overlaps of tissue, they don't look much when wet, but rubbing back takes much longer than you might think. A good trick with the edges of tissue is to leave the 2 or 3 cm (1 inch or so) of the edge dry. You can then pull them away from the wetted, laid up tissue, whilst holding the wet tissue down with a roller or brush. This way the dry edge separates from the wet tissue, which feathers out.  It then blends in much better.

6. I used 40 or 60 grit paper to rub down the surface after the tissue. The tissue surface may look fine but it's usually not. Don't make the mistake of believing you can just over coat lumpy tissue with gel coat and it will be OK. It won't. Make sure you shape the tissue layer before you gel coat over it.

7. Gel coat. There are a few issues here. Gel coat is not intended to be applied to the finished surface. It is designed to be applied to the mould and covered in mat. Its thixotropic so that it adheres well to vertical surfaces but it won't flow out so if you use a brush it will leave a very lumpy surface. Finally, oxygen inhibits the polymerisation process so the surface layer will be less "set" than the rest, meaning that the top layer will remain slightly sticky

8. Because of the above, brush painting gel coat over the tissue isn't a good idea. Because its not designed to flow, you won't get a flat surface. You can try to thin it out with layup resin, but I've found that isn't very effective. The answer for me was to use gelcoat thinned out a bit with lay-up resin, laid on with a solvent resistant six inch, short pile roller. This will still give you a finely stippled surface but its relatively easy to rub back. The more professional approach is to use a spray gun intended to spray gel coat, which may well give a better surface finish. Theres a nifty one available that uses a disposable mixing cup as the reservoir HERE and the results look good.

9. Sticky surfaces: I found several solutions to this on the web:

(i) just leave it for a week or so and rub back with 60grit. Works for me. You need plenty of 60grit as it will clog, but once the surface was gone I found it was OK. The disadvantage is it needs lots of rubbing down, so make a lot of dust.

(ii) Use a wax additive such as this one. Its mixed in with the gel coat and floats to the top when applied. This apparently forms a barrier that prevents oxygen getting at the surface and so gives a tack free surface. I didn't use this approach as I was concerned about surface contamination with the wax, which might interfere with the paint. I couldn't find any information on this issue, so elected not to go there. I didn't want to find out whether it worked 5 years after I finished the car.

(iii) Over spray the applied gel coat with PVA. This apparently then dries to form a seal and can be wiped off when the gel coat is set. I haven't tried this yet but I will give it a go later and report back.

(iv) Overlay the gel coat with a plastic sheet when it is partly set and remove it when fully set. Hmmm, i tried this and the sheet stuck to the gel coat and when removed left odd waves, where the sheet wasn't quite flat. I also tried using cling film...... Just don't bother. Might work on a flat surface, but on compound curves this approach is hopeless.

Here are some pics:

Here is one of the wheel arches on gel coat. You can see the stippled surface and the effect of not paying attention to the edges of the sheets of tissue. While it all looks OK......

Heres what it looks like when flatted out......In this case the surface tissue was applied with a brush. It will need another two coats of gel coat.

Here is the passenger side door after two layers of tissue applied by roller.

and here after two coats of gelcoat applied by roller.

This shows the process of tissuing the passenger side forward of the door. 

Roof, might need another coat, but turned out nicely.

Gratuitous Photos

I took the car outside for some air for the first time in ages, so I thought I'd add a couple of photos of where I am now. Pretty much all the cracks done bar a couple on the rear and a new one I found on the passengers door frame.

Rather pleased with myself!

Fuel Tank Install.

After 18 months worth of grinding out, re tissuing and rubbing down, I have had enough of crack repair for now. I am not finished, but I just can't face another. I will need to go back and re visit the driver's side because, the wheel arch lip needs repair, but right now I just need to do something else. So, on to the petrol tank.

The car's petrol tank is original and looked fine, except that it had a hole in it! TVR Vixens are prone to this because the factory placed a felt pad between the tank strap and the tank, which, naturally, absorbed water and then progressively rotted through the tank. I could have bought a new tank, but I decided to get the old tank repaired, which, as it turned out, cost not much less. Ho Hum.

The tank is held in by a couple of tank straps, that are glassed in to the floor of the rear recess. Unfortunately, the recess gathers any water that leaks into the back of the car through the window seals and poorly sealed wheel arches, and rots out the tank straps.

After removing the remains of the tank straps, I made a mod that I have seen on a slightly later car. I installed a couple of glassed in wooden fillets to take the tank straps. This means that any water that does get in won't be lapping around the metal straps.

I made up some new straps from 20mm steel and added a re-enforced return on one end and a captive nut to the return on the other and glassed these onto the wooden fillets.

Thats the access hole for the petrol tank drain in the middle, which is covered from the underneath with a simple flat piece of fibreglass, that's screwed to the tub. It looks like it might also serve to protect the tub from the heat of the exhaust. It had been accidentally glassed in so I had to cut it out. I am planning on using a stainless protection panel there instead. 

re install the nice shiny tank:

 I also made up a new rear deck from a pattern kindly provided by Tony Giddings (Thanks Tony!). See Tony's Vixen restoblog here

Note that the deck has to be relieved to take the top of the fuel sender. This is, I am told, standard.

Then I made up a new spare wheel retainer, which was missing from the box of bits. I neglected to take any photos as I was building it but it's a very simple construction. The shaft is 1/2"bar with a UNC thread. The rest is 25x6mm flat bar. The bracket has two 3/8" captive nuts to attach it to the deck, and a 1/2" inch captive nut to take the bar. 

Thinking on it some more I could have just tapped the flat, which probably would have been better, but anyway, here it is finished:

All done

Oh, just in case you were wondering (because I definitely was before I got help) the front of the deck rests on the wooden batten on the front lip, and the rear of the deck is unsupported. The deck actually rests on the top of the tank, supported by a pad. Presently mine doesn't have the pad because this version is just the prototype. On reflection I think it needs to be thinner (maybe 9mm?) and where it fits around the wheel arches I need to cut it more accurately to the arch, once the sound deadening and the vinyl covering are on. The deck should be screwed to the wooden batten to hold it in place too.

Note how the spare sits snuggly behind the driver' seat, not in the middle of the rear deck. This surprised me a little, but it does give more space to carry stuff on the shelf. The spare should also have a vinyl cover.

Cracks Cracks and More Cracks

And so to the bodywork.

Well, what can I say. The body tub is covered in cracks. For example, I would say about 50% of the roof has cracked gel coat, you can see it here in this older photo

Its not quite as bad on the other side, but it's still pretty daunting.

The car has clearly been in one or two accidents in its life and some of the repairs have not been well executed. I suppose that's not surprising; someone once said that its the fate of sports cars to be owned by a succession of ever more impecunious young men until, eventually one of them drives it into a ditch.

The whole extent of damage to fibreglass in an accident is hard to see unless you take all the paint off the panel. When you do that you can see all the cracks that emanate from the point of contact and the structure is so much more of a mess than it first seems.

The worst impact damage on this car is on the rear passengers side, where it looks like the whole B pillar has been separated from the body. The whole panel from the door back to the rear panel is cracked.

When it was repaired, new glass seems to have been laid up behind the damage, in the wheel arch,  and the surface was filled and painted over. However, it seems that the glass was laid up without adequate preparation of the existing surface, and it came away in my hand with a bit of a pull. This damage is all fixable with a bit of patience, but the amount of work here makes it worth considering a repair panel. The rest of the cracks I will just tackle one at a time until they are all done...

It has been suggested I should get a new shell, and save myself the bother but 1). that's not the point of this project. I want to save as much as I can of the original car, and 2). its far too expensive an option right now, so onward and upward....

Here is what the roof looks like now. This took me about 15hrs work, but it still needs a bit more to tidy it up.

I thought it might be useful to someone if I set out how I go about dealing with the cracks. It might save someone a bit of time. The method is based on "How to restore fibreglass bodywork" by Miles Wilkins. 

The cracks you see in the surface of fibreglass cars originate from stress in the surface gelcoat, from flexing or impacts. Often you get these around door handles from over enthusiastic use of the handle, or on the bonnet from stone strikes, or like mine, from accident damage or rough handling of the shell. 

The crack seldom goes deeper than the gel coat. In fact, my Vixen, like most early TVRs, actually doesn't have a coloured gel coat at all. I am told TVR used a clear gelcoat in order to be able to see any issues in the layup resin.

Heres a set of cracks around my fuel filler as an example:

The shell is very thin at this point. It actually looks like maybe only 2 layers thick or maybe even just one. These cracks look like they have been caused just from flexing when the filler hose is left to hang on the car while it fills. On cars like TVRs, with no colour in the gel coat, you can see them much more clearly if you illuminate them from behind using a torch, like in this picture. I've now added a couple of layers of mat behind here to stop this happening again.

The trick is to remove the gel coat layer around the affected area, leaving a good inch or so beyond the end of the cracks and making sure to feather out the edges. You then lay in a layer of fine fibreglass tissue, with a good helping of resin. If you have had to grind out a lot, then lay in two or three layers. Then you sand back and thats it. I find its easier to deal with a small area at a time, so the the contours of the remaining bodywork guide the re finishing.

I have used a grinder with a flap wheel attachment, which works very well, but is very noisy. For smaller areas or single cracks I have found its easier to use a power file, like this one:

The filter is useless when you are grinding back fibreglass by the way!! Its very quickly overwhelmed! I use 60 grit bands. They do the job very well, although they do leave a lumpy surface.

The best approach I have found, however, is to use mini flap wheels. I found some good ones on Amazon very cheap (5 for less than £10). You can get them in 60 grit, they last quite well and they whip through the gelcoat easily when fixed in my cordless drill. They also don't leave a lumpy surface like the power file does on large areas. They make feathering out a doddle too.

This is the first area ground back. I used the power file on this one hence the lumpy surface. This actually makes refinishing the laid up mat more difficult as it seems to lead to more air bubbles and surface pock marks.

I use a torch again to check that all the cracks are gone. I usually paint in a layer of resin first and then layer on the roughly shaped tissue. The first dab of resin will show up any remaining cracks very clearly. If you have any cracks left, you can quickly wipe away the resin and regrind.

Wet out the tissue with a generous amount of resin making sure not to leave any air bubbles. I use a disposable paint brush, with the bristles cut right back to about an inch long and a stippling action to drive the resin into the mat and wet it out properly. I clean them out again in acetone afterwards and they can be used many times, or at least until you over do it with the catalyst and the gel goes off before you get a chance to clean up! 

Then, when the lay-up is still "green"(before the resin is completely cured, no longer wet, but still very slightly soft), roughly shape it with a "Surform" type device. If you don't do this, you will spend a huge amount of time rubbing back! It also creates far less dust.

On which point I ought to say here, that you should not be rubbing down fibreglass without a proper face mask (not one of those nasty disposable ones, that don't seal on your face, but one with a seal around the nose and mouth and good quality replaceable filters).

Once the layup has cured I work up the surface with 60 grit on a block and then work up the grades to a 400 grit. This is the same area after 250 grit.

If you do end up with dips/air bubbles in the surface, I found its better to fill them with a small piece of tissue and a drop of resin, than to try and fill them with resin. Somehow resin alone, seems to always need another fill, no matter how small the dip.

You should never be tempted to grind out the cracks and then fill them with filler. The filler and resin areas have different hardness and so the area will soon crack again. Also over time the filler shrinks slightly and so you can see the repair.

Right now I am about 25% of the way through the cracks. I'll post up anything else interesting that turns up.

March 2018
So, here we are halfway through March 2018. I have managed to get out and do an hour or so on the car most weekends and I would say I am now about 2/3rds of the way through. I have finished the roof, the rear deck, the drivers side front and drivers side rear (pretty much).

Whats left to do is the area below the rear panel, where it curves away under the back. I know there are some cracks there, but I haven't managed to remove the last of the paint from this panel yet; I may have to hoist the tub up to get at it. Then of course there is the rear quarter with the crash damage, and the front side panel, which also has some damage.

Just as a bit of a break from constant rubbing down, I thought I would fit the drivers door.

So, here it is fitted:

The gap isn't awful. I am not sure whether I will reduce it or leave it as is:

28th May 2018

Well, I'm now at the UK's late May bank holiday and sneaking a bit of work on the shell. I have repaired a large dent in the front nearside and sorted out the various star cracks in the area.

The large grey patch is the glassed area. It's grey because of the new resin and tissue, I didn't use any filler here. It took me about 3 weekend's worth of spare time, maybe 8-10hrs, to get this right and fix the rest of the damage. There was a lot of damage in this area, the pointed part of the panel had been knocked off and crudely repaired too, so that had to be completely reshaped. There was damage to the wheel arch lip too and some fiddly cracks to deal with on the inside of the air vent that are a bugger to get to and shape. The screw holes for the trim pieces over the vents have also been filled in as they were cracked and worn to over sized, as have a couple of holes that look like they were for a bonnet strap.

Sadly the harsh lighting of the photos show I still have a little work to do to get this perfect.

Today I decided to fit the passenger door and take a look at the fit and adjustment options. Its amazing how much easier this is when you have reconditioned hinges (Thanks Adrian). I managed to get a reasonable fit at the front

but there is still a lot of work to do on the sills where there has been some collision damage in the past, that is poorly repaired. 

The fit at the back is awful, but this will be sorted out after I have glassed in the repair panel to the rear quarter and had the body bonded back on. Again the harsh lighting shows how much work I still have to do on the door skin, which has been plastered in filler.

I think I am likely to have to extend the back of the door by a couple of millimetres, although there may be some scope to build up the tub as well.

15th July

Its mid summer and very hot in the UK; well, for us anyway, so the garage is stifling. I have managed to get out there and do some more work on the cracks and I am inching my way towards a point where it's time to replace the rear quarter. The passenger's door is off again, and I am working on the B post, where the cracks from the impact on the rear quarter have propagated around onto the lock surface. 

Theres quite a lot of old repair work to sort out around this area too, especially inside the wheel arch, where, having removed most of the paint and road dirt, I have found that a lot of the old repairs seem to have deteriorated due to dirt and water getting into the lay up. 

Here's one behind the B pillar. A fillet of glass laid up to deal with a crack separating the B pillar from the inner tub wall. I had cleaned off all the paint as best I could then thoroughly washed down the inner arch. You can see that the fillet is lifting off at the bottom.

and it pulled straight off with a tweak from a screwdriver

So that lot had to be repaired again; and so it goes on.

I thought I'd share a trick I picked up. I can't take the credit for it but, I thought it worth sharing.

The rim around the rear window opening that takes the window rubber is very thin and quite delicate. Some parts of it have been damaged on NPY and after several poor attempts to fix them I found this approach.

I made a temporary mould of a good part of the lip like this:

First cover the area with packing tape smoothed in well. It has a very shiny surface and so works well to aid mould removal. I added a bit more up-stand behind with a scraper.

Henry didn't know what to make of it all!

Lay up about three layers of surface tissue. If you don't do this you will lose the lip detail, because the heavier mat won't conform to the shape. Follow this up with three layers of normal mat:

Pull off the mould when its hardened and remove the packing tape

This is one of the worst sections of lip

Cut it back and grind down the edges behind for about half an inch all round, so its good and rough and clean:

Then cover the mould in packing tape. Fix it over the area and hold in place with a couple of mini clamps, then lay up the repair. I found it works best if you start with a couple of layers of tissue first followed by a couple of layers of mat.

Rub back and hey presto!

Actually this needs a little bit of extra lay-up behind, but you can see how it works! It saves a lot of time and actually works quite well.

22nd September

So, now we are into September and I am onto the dreaded rear quarter. The rear quarter repair panel arrived from Duncan Reuben at TVR Classics. Here it is:

I am not going to use the whole repair as I have managed to repair some of the damage above the wheel arch moulding, and I would be worried that the tub would not hold its shape if I cut through the B pillar.

Cutting out the damaged area was pretty nail biting:

But nothing like as nail biting as cutting into the repair panel:

I just have to finish off trimming the panel, then cut the tub to fit. I am calling it a day there and coming back to it with fresh eyes tomorrow.

So, here is the rear quarter panel tacked to the car. I held it in place with butterfly nuts and washers, then glassed two layers behind the panel, 

 when that was set, I moved the butterfly and repeated until the whole panel was done:

 then ground out the join until it was almost through the panel, feathered it out about 2 inches each side, laid up a thin strip , then a slightly wider strip then several layers of tissue. When it was still green I Surfomed it and then rubbed back with 60grit as usual. It took a bit of getting right. Here it is almost done. Ive managed to get some bubbles in the resin by the door, so I ground those back and filled with tissue again. Next step is to re attach the wheel arch to the panel from inside.

Original state of the panel for comparison:

wow, what a difference!







9th March 2019

So, pressing on: Time to deal with the passenger door fitting. It originally looked like the door fitted quite well at the front but the fit was very poor a the back. However, this arrangement meant that the lock didn't engage sufficiently with the striker plate, so in the end, I decided to move the door back about half a centimetre. The door should now fit at the back but the leading edge is no longer satisfactory, so...

I got rid of as much of the filler as I could from the front of the door, then I ground the front edge of the door down to a gradual taper over about 2 inches. I then taped some aluminium foil in the door gap and laid up the mat to fill the gap. When it was still green, I was able to run a knife down the gap and then use sandpaper to expand it and was eventually able to open the door! I won't do that again, the foil got caught up in the lay-up and had to be picked out. Better to stick to the tried and trusted packing tape I think.

The next problem was that the sill had been badly damaged, probably in the same accident the ruined the rear quarter, so that all had to be repaired. Rubbing down the filler at the bottom of the door revealed yet more damage to the door skin, so the bottom of the door was ground back and rebuilt as well. Finally, once the door bottom was repaired, the bottom door gap was adjusted by sanding back the door bottom. The gaps aren't too bad now. I may still have to do something more at the front but I am quite happy with it at the moment.

I don't know what's going on under the rest of the filler plastered all over the door skin, but I suspect it's more crash damage. I am probably going to leave this as is.

As an aside, this old filler is quite odd; I thought the cat had peed in the garage until I tracked the smell down to the dust this stuff makes when sanded down. Nasty.

So, now I am pretty much done with the passenger side. I just have to adjust the way the door shuts onto the striker plate, because with all the damage and door adjustment, the plate is no longer in the correct place.

Apart from that, the only panel I have left is the one that tucks under the back of the car and that is next. Should be a doddle after all that.....