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.....