star cracks

[b1zbaz]

does anybody know how to get rid of star cracks my midas has got a bit of damage and my dads mini minus has got quite a few on the bonnet which we need to sort before getting it resprayed
thanks for your time baz manchester

[Hans Efde]

You'll have to open the cracks with a Dremel or so. Then you can fill the cracks with a special repair filler and finish the car off for spraying. It's best to go to a GRP specialist for the proper materials.

[wolfie]

Spent plenty of time sorting this problem for people. To start with you need to drill a small hole at the end of every line of the crack (this stops the crack spreading). Secondly you want to sand down the crack and fill with fibreglass resin. Once this has cured(which wont take long) a quick skim of normal body filler to get the surface blemish free. Remember the THE most important thing is drilling the holes! if you dont do this the crack will reappear and spread no matter what you do. Hope this helps

[b1zbaz]

thank you for your help i never even thought about drilling wholes at the edge of the cracks i will try them both its on a minus bonnet so the fibre glass is very thin thanks for your help

[johnonthetyne]

i watched ed china on wheeler dealers doing this last week, i cant remeber which car it was though.may have been bmw 850

[MikeW]

Hi

You need to grind out the crack at a shallow angle with an abrasive disc (P80? - been a while), then and then add fibre glass matt or tissue and resin, then fill and paint. There is no quick fix.

The best book for grp car repairs was by Miles Wilkins, 'How to Restore Fibreglass Bodywork' - unfortunately long out of print. But you can now buy a reprint from a Lotus Books in Germany. It comes combined with Wilkins' book on car painting. See: http://www.lotus-books.com/additions.html You can pay in £. Order form: http://www.lotus-books.com/order.html

Highly recommended, particularly as very little has been published on grp car repair. Recent articles in Practical Classics have been wrong, it won't work long-term to just do a narrow grind out of a gel crack and put resin/'gelcoat' and/or filler and then paint. This contradicts info they published years ago from Miles! Got to do wider grinded area and then mat/tissue and resin, fill and paint.

If anyone needs to buy fibreglass supplies in Scotland, I've found Allscot very helpful. Trade prices, DIY quantities, and open late some evenings as well as Sat morning. And no, I don't work for them, or get a discount!

Web: http://www.allscotltd.co.uk

They're in Glasgow, but do mail order

Cheers
Mike

[johnnyfixit]

Probably one of the most difficult repairs to effect permanently is gel coat cracking caused by impact.Even when the cracking is removed by rubbing down after painting it will reappear as the crack will not have been removed to its full depth of the gel coat.The crack may even penetrate into the resin layer even though the glass structure does not appear to be damaged.The sure way of dealing with the problem is to cut the area out,relaminate,rebuild the gel coat surface and fair to shape.The alternative is to back up the area with more laminations,grind out the damaged area with a disc grinder including some of the glass in the heavily cracked areas and then re-build if necessary with glass,resin and gel coat and /or body filler.