It is currently Sun Sep 23, 2018 11:59 am




Post new topic Reply to topic  [ 16 posts ]  Go to page 1, 2  Next
Bodywork repair advice 
Author Message
GTM delivered

Joined: Sun Feb 12, 2017 9:25 pm
Posts: 43
Location: Peterborough
GTM: Cox/Coupe
Post Bodywork repair advice
Hi guys,

Can anyone advise on the best way to repair the below? There had always been a small hole there since i've owned the car about the size of a pea but the missus managed to bang it carrying the baby car seat passed earlier!

Image2018-02-28 16.08.51 by Pete Clayton, on Flickr

Image2018-02-28 16.09.02 by Pete Clayton, on Flickr


Wed Feb 28, 2018 6:09 pm
Profile E-mail
Part built GTM

Joined: Sat Mar 12, 2016 7:05 pm
Posts: 126
Post Re: Bodywork repair advice
Pete can you get at the back from the boot or is it double skinned ? I would glassfibre from the rear the hole and the area above that is cracked with 2 layers 300 csm (aluminium gauze can be used at the back of the hole to support the chopped strand mat) drill a small hole at the end of each crack to stop the gel crack spreading before you glass the back. Once back has set grind along cracks and feather edge of hole with cutting disc build up hole with csm from front then use glassfibre tissue in cracks & to finish where hole is until built up almost level you can finish with a very thin skim of filler to finish not to thick as it can sink with age and certain paint thinners. If you do not glassfibre the surfaces filler will just crack out after a few months
Ian


Wed Feb 28, 2018 7:26 pm
Profile E-mail
GTM delivered

Joined: Sun Feb 12, 2017 9:25 pm
Posts: 43
Location: Peterborough
GTM: Cox/Coupe
Post Re: Bodywork repair advice
Thanks for the advice. I figured using some mat from the rear would be the best way. There is another skin slightly behind I think it must be the boot compartment? I guess I may need to cut an access hole so I can repair it and then glass up the hole I make.


Wed Feb 28, 2018 8:21 pm
Profile E-mail
Part built GTM

Joined: Sat Mar 12, 2016 7:05 pm
Posts: 126
Post Re: Bodywork repair advice
It is a bit time consuming building up the layers but the shell looks in really good condition otherwise and there is nothing worse than getting nice new paint on then in 6 months a crak appears all the best
Ian


Thu Mar 01, 2018 9:07 am
Profile E-mail
Ready for SVA

Joined: Tue Sep 09, 2008 4:46 pm
Posts: 322
Post Re: Bodywork repair advice
I'm no fibreglass expert but that looks like a void between the gel coat and the actual fibreglass structure -- maybe grind a little out around the hole to see what you're got then sort with filler or gel.

Steve


Thu Mar 01, 2018 10:38 am
Profile E-mail
On the Road
User avatar

Joined: Tue Oct 30, 2007 8:44 am
Posts: 654
Location: Chester le Street
Post Re: Bodywork repair advice
Quite right Steve.

It is a void between the CSM laminate and the gelcoat which is why it's cracked away like that.

Is the CSM laminate actually damaged?

If so then you need to repair it as described above.

If not then you only need to repair the gel coat.

The repair itself is not hard but getting a colour match definitely is.

First you need to break away all the damaged and cracked gel coat to see the extent of the problem.

If the void is big you could partially fill it with one of the fillers that are reinforced with glass strands.

The final layers should be in gel coat or gel coat filler (a thicker version available from East Coast Fibreglass).

Leave it slightly proud of the surface so it can be sanded back and polished to match.

_________________
GRP rules!


Thu Mar 01, 2018 11:03 am
Profile
Part built GTM

Joined: Wed Sep 30, 2015 8:25 pm
Posts: 145
GTM: Cox/Coupe
Post Re: Bodywork repair advice
The good thing about modern 2k paint is it is much stronger and is a bit flexible, you still need to repair properly as mentioned but an old GRP shell will last a lot longer before cracks appear with a good 2k paint job.


Thu Mar 01, 2018 2:45 pm
Profile E-mail
GTM delivered

Joined: Sun Feb 12, 2017 9:25 pm
Posts: 43
Location: Peterborough
GTM: Cox/Coupe
Post Re: Bodywork repair advice
Looking at it again I think you guys are right, it looks like it's probably just the gelcoat. It feels solid and looks undamaged behind it so hopefully will be a fairly easy repair then. I'm not too worried about matching the gelcoat as it will be painted in the not to distant future.


Thu Mar 01, 2018 6:10 pm
Profile E-mail
Part built GTM

Joined: Sat Mar 12, 2016 7:05 pm
Posts: 126
Post Re: Bodywork repair advice
Pete if you use gelcoat for the top layer you need something like flow coat designed to set without being covered in the mould but as you are painting i would not bother
Ian


Thu Mar 01, 2018 8:16 pm
Profile E-mail
GTM delivered

Joined: Sun Feb 12, 2017 9:25 pm
Posts: 43
Location: Peterborough
GTM: Cox/Coupe
Post Re: Bodywork repair advice
I don't plan on using gelcoat for the top so should be ok. Thanks for the tips and pointers chaps :)


Thu Mar 01, 2018 9:42 pm
Profile E-mail
GTM delivered

Joined: Thu Nov 22, 2007 10:31 am
Posts: 49
Post Re: Bodywork repair advice
Looks like a typically bridged piece of laminating i.e where the laminator has not fully pushed the laminate onto the the gelcoat and not consolidated the stack hence the original pea sized hole and the eventual breakout through a minor impact.

I would recommend purchase a copy of Basic Fibreglass Techniques - How to Fibreglass DVD (section 4 on repairs). It will give you the way to keep your GTM Coupe in fine fettle. The presenter is/was one of our members and was the builder of a Coupe with a fibreglass chassis - Mr John Dickens.

If you're an impecunious youngster the youtube offers some good fibreglass repair videos, but I would approach the problem thus.

Wear eye protection and gloves and a long sleeved shirt – Fibreglass dust really itches on your skin.

Carefully break out all the remaining void and enlarge any residual cracks using a screwdriver and a hacksaw blade. Sand the damaged area (120 grit) so reasonably smooth. Clean the area with acetone and paint brush to remove all dirt, grease, wax and to soften the resin and then wipe the whole area with an acatone dampened cloth.

Catalyse and mix some Davids isopon P40 (or similar) and fill the hole to 80%, It would be usefful here to use a couple of lollypop sticks to manipulate the P40 onto place.
Once dry, sand the P40 and catalyse and mix and apply some P38 to fill the hole to 98% so the filler is a mm or so below the final surface.
When dry sand the p38 and wipe again with an acetone dampened cloth and then catalyse, mix and apply some thich gelcoat and paint on, cover with polyester release film or Mylar, tapeing it in place.
Leave to cure, remove tape and mylar and sand with 1200 grit wet or dry. Polish with Farecla G3 Paste( or similar).
Stand back and smile.
BTW all these products are available from East Coast Fibreglass on-line.

To keep warm, just now, with some cloth and the Farecla you have laft you could do the whole car and realise its true colour! and then apply wax - beautiful.


Sat Mar 03, 2018 2:06 pm
Profile
On the Road
User avatar

Joined: Tue Oct 30, 2007 8:44 am
Posts: 654
Location: Chester le Street
Post Re: Bodywork repair advice
Elansprint wrote:
Pete if you use gelcoat for the top layer you need something like flow coat designed to set without being covered in the mould but as you are painting i would not bother
Ian


Flowcoat has a wax additive to prevent it being sticky after it sets.

If you use Flowcoat you won't be able to paint over it.

Standard body filler will certainly fill the hole but gel coat filler will leave you with a surface that exactly matches the texture and hardness of the original.

_________________
GRP rules!


Sun Mar 04, 2018 9:57 am
Profile
GTM delivered

Joined: Sun Feb 12, 2017 9:25 pm
Posts: 43
Location: Peterborough
GTM: Cox/Coupe
Post Re: Bodywork repair advice
Well i've had a go at it. I opened up the hole a bit until there were no more cracks or loose bits. I cleaned it up with some acetone and then used some stranded filler (horrible to work with!) to build it up and then sanded it back and skimmed with body filler.

This is the result, it still needs a light rub down with some fine paper.

Image2018-04-25 18.00.23 by Pete Clayton, on Flickr

Image2018-04-25 18.00.26 by Pete Clayton, on Flickr


Wed Apr 25, 2018 10:29 pm
Profile E-mail
On the Road
User avatar

Joined: Sun Oct 19, 2014 10:10 pm
Posts: 720
Location: Bristol
GTM: Spyder
Post Re: Bodywork repair advice
Looks pretty good to me although the colour match is a bit off :wink:


Thu Apr 26, 2018 7:03 am
Profile E-mail
On the Road
User avatar

Joined: Fri Sep 28, 2007 7:39 pm
Posts: 568
Location: Aberdeenshire
GTM: Cox/Coupe
Post Re: Bodywork repair advice
sanzomat wrote:
Looks pretty good to me although the colour match is a bit off :wink:


fade to grey I think its called.

Visage 1980

_________________
Member No 1185


Thu Apr 26, 2018 2:06 pm
Profile E-mail
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 16 posts ]  Go to page 1, 2  Next


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © phpBB Group.
Designed by Vjacheslav Trushkin for Free Forums/DivisionCore.

phpBB SEO