32 replies to this topic

[theolodian]

I agree about it not being osmosis of the layup, but I think it is more than what people normally think of as 'paint prep'. These are large pieces of composite and any method other than prepreg is going to have lots of small voids. If they just use normal filler on those voids then that filler can have water issues, and then leave a hole when the bubble falls off. Those voids can also store water and other crap, making any filler or paint prep tricky.

[Horace]

I think a comment from Mr. Tidy's Dad could be useful?

[turbobob]

I agree about it not being osmosis of the layup, but I think it is more than what people normally think of as 'paint prep'. These are large pieces of composite and any method other than prepreg is going to have lots of small voids. If they just use normal filler on those voids then that filler can have water issues, and then leave a hole when the bubble falls off. Those voids can also store water and other crap, making any filler or paint prep tricky.

Normal filler is also porous, so that is a no no. The gel coat / resin is the top layer for seal and finish.

Also, I have to say whilst I had some degree of blistering on my rear clam from last year, the winter made it FAR worse. I put up a thread of before and after of the blistering on mine - Bad blistering

Most of that blistering happened after standing water (foolhardy me having too small a cover) froze on the rear clam.

[slindborg]

loads of paint has fallen off round my lower clam to upper front clam join (near the headlights) where Lotarse put filler in and made the join 'ok' with a stick or something I now have some GRP filler paste stuff thats not normal filler. Should be good enough to sort the door out

[Crazyfrog (Fab)]

This would suggest the clams weren't stored very well before painting and / or the gel coat (the layer to protect from moisture absorbtion) is crap.

no no the clam was made in france by a compagny i know and they used to cut it with water equipment and some batch left france not very good finnish ie dryuing time
i have a mine for eight years with no problems what so ever maybe they new i was a special customers eight years ago and bought a right batch

[FLD]

Polyester gel coat is also slightly porous. It can make moulding difficult if done under high vacuum as it forces the moulding resin into the mould. In these situations a vinylester is favourable as its far less porous. Might be an idea for repairs?

[turbobob]

Vinylester is from what I can gather a popular material for fibreglass repair (top layer / gel coat). The other popular material is epoxy resin. This is also resistant to water absorbtion, strong and good for smoothing off in readyness for paint prep.

[TheStotts]

A couple of pics of my pikey style blistering

Can anyone recommend a specialist near Northampton that might be able to sort this out?

Rear wheel arch



Rear clam bubbling



Around engine cover



Base of doors

[techieboy]

Can anyone recommend a specialist near Northampton that might be able to sort this out?

Silverstone Paint, think MandarinVX(?) had a long chat with them about cures for blistering a while back.

[TheStotts]

Can anyone recommend a specialist near Northampton that might be able to sort this out?

Silverstone Paint, think MandarinVX(?) had a long chat with them about cures for blistering a while back.

Thanks, I'll give them a ring

[petrolhead1]

I have no idea if they are any good but a quick Google came up with these guys. http://www.paintwrx.com/91902.html

[TheStotts]

I have no idea if they are any good but a quick Google came up with these guys.

http://www.paintwrx.com/91902.html

Interesting. Booking the car into Guglielmi for a geo next week so will have a look.

Thanks

[Crabash]

I had my rear clam sprayed 4 times for bubbling round the hatch, by vauxhall, they refused a new clam. It returned after the 1st sign of frost after every painting, and after I stopped them painting over and over due to them not doing a good job it has got worse every winter. I just left it figuring when it got really bad I would get the whole lot done. I have a mate who I know used to paint a lot of kit cars, been a while since I saw him but he always seemed to have a lot of respect for his work, I will call in and speak to him about it soon.