Crazing, spidering - HELP!

[gw1]

I know the bonnet on my S3 isn't original and had it resprayed at the begining of the year. It had a lot of crazing on it and the guy who resprayed it said he spent a long time taking it down so they wouldn't come back . I'm now very unhappy as all the crazing is back. I only run the car 6 months of the year so now is a good time to try and get it sorted. I don't mind the work invloved even if I have to take all the paint off and start from scrach , I just don't want it to come back . And suggestion ??

[NickP_S2]

To totally eliminate cracks and crazing you will need to rub the affected areas down using P600, then P800 wet-n-dry. Remember to use a rubber-block while sanding as it will prevent you from rubbing finger sized grooves into the paintwork.

You will need to rub down an area surrounding the cracks large enough so that the difference in paint thickness is not noticeable. If you have lots of cracks/crazing its probably best to remove all the topcoat from the entire bonnet to get a decent finish. Once you have eliminated all the cracks etc use progressively finer grades of wet-n-dry.

Also remember that your cracks/crazing may be due to damage on the underside of the bonnet causing the fibreglass to stretch when you open or close the bonnet. In which case it will be neccessary to repair and respray that side too.

For small cracks use a fine filler which comes as a paste and requires no hardner, I forget the name of the stuff, it was red coloured though.... Paint with a thickish coat of filler primer to start off. Rub this down with fine grade wet-n-dry. To get a great finish spray a thin coat of a dark colur all over the bonnet, and rub it away with P1200 and the sanding block. This will ensure the primer is smooth and not pitted or 'orange pealed'.

To get the top coats done you will need a heated spray booth and probably best to leave this to a pro.

[Notanutter]

gw1 said:

It had a lot of crazing on it and the guy who resprayed it said he spent a long time taking it down so they wouldn't come back

I'm really not an expert on fibreglass but feel for you, and do know that once you've got a crazing problem it can be a bu@@er to get rid of. My first experience of fibreglass was in 1969 when I whacked my Fairthorpe (oh yes I do go back a long way...) into the back of a bus when the brakes failed a bit. I pretty much stuck it back together with Isopon, and painted it with Dulux coachpaint and a paint roller, it actually looked pretty fine. A few years later I started using fibreglass in large model aircraft construction and discovered how sensitive the stuff is to mix strength, temperature/humidity, and proper preparation and finishing. In the late 80s I got into realy old TVRs and bought a Grantura, it too had been part repaired and try as I may I couldn't get rid of one star mark on the bonnet and a crack below the rear screen. Then earlier this year I bought an S3 which (unknown to me) had been stuffed into a tree by a previous owner, repaired, and hey ho the cracks in the bonnet kept coming back. Something to do with flexing of the bodywork, vibration, that kind of thing. So get a real pukka expert to fix it including cutting bits out if necessary, certainly just covering over with filler is b@lls and a waste of time and money.

[nicbowman]

Hi, after long experience with fibreglass cars, I can categoricaly state that filler does not work. You need to grind out the affected gel coat with an angle grinder just a couple of mm into the fibreglass, then fill the void with fibreglass matting and resin. It is important to not use too much resin, and plently of matting. Then flatten, ideally all done dry to avoid any water migration into the fibreglass. If there are large areas, forget it. Small bits, (an inch or two) are okay for diy. Maybe better to buy a replacement bonnet? You can find plently of stuff on how to do this on the internet. If I get a minute today I will look out a link. Best regards

Nic

[KentishS2]

TET Mouldings

www.b-link.co.uk/tet/tet/sseries.htm

[RichardR]

gw1 said:

I know the bonnet on my S3 isn't original and had it resprayed at the begining of the year. It had a lot of crazing on it and the guy who resprayed it said he spent a long time taking it down so they wouldn't come back .

Surely, if you paid the guy specifically to address the crazing problems, you can go back to him now and get him to carry out the remedial work?

[Colin Blues2]

If you want to do it yourself then I can recommend the Osprey Restoration Guide - How to Restore Fibreglass (author - Miles Wilkins), there's a whole section on cracks and crazing and how to repair them.

The advise is to grind out the crack and re-laminate with matting and tissue and possibly strenghten from behind if necessary with more matting.

I would have thought that the person who repaired it last time would have given some sort of guarantee on his work, although I can understand if you are reluctant to go back to him again.

[RichardR]

Colin Blues2 said:

I would have thought that the person who repaired it last time would have given some sort of guarantee on his work

Exactly...when Harrisons repaired my bonnet they provided a 3 year guarantee, and when a spider crack appeared in the middle of the bonnet 11 months later they took it back in and did a repair and full respray on it.

[gw1]

To save money I took a chance and got the respray done on the side, my own fault I suppose. Could someone show me how to upload pictures and I can show the extent of it. Why does it matter if I have a little or a lot? Could I just lay fibre glass over the whole area?