What's the best way to prepare a fibreglass car?

[clivesroadster]

Is it better to bake the car first to allow any air bubbles to rise, then sand the tops off and fill? If so fill with what?, resin and surface tissue? any holes may be quite small? P40 fibreglass paste? Can you use a heat gun to expose air pockets? OR is none of the above needed if the car is not baked in an oven when painted? Does it need to be baked to achieve a professional finish? Also I hear filler sinks after a while, is that correct? if so what can be done about this problem.

Sorry for all the questions guys but as you can tell I am a newbie to paint.

 

[TAZ]

If the fiberglass is quality fiberglass, there really shouldn't be any bubbles.
It should have a nice smooth thick gelcoat. If you do have a few, break them open, sand the area and then fill them.
Then 180 grit the complete surface and prime with a good epoxy primer.

No need to bake to achieve a professional finish. This is up to the actual sprayer to apply a nice finish!

 

[TAZ]

If the fiberglass is quality fiberglass, there really shouldn't be any bubbles.
It should have a nice smooth thick gelcoat. If you do have a few, break them open, sand the area and then fill them.
Then 180 grit the complete surface and prime with a good epoxy primer.

No need to bake to achieve a professional finish. This is up to the actual sprayer to apply a nice finish!

 

[clivesroadster]

Thank you for the reply Taz. There are no bubbles present when you look at the gel coat, BUT I hear on a hot day IF there are any bubbles under the gel coat these may be seen as the air expands under the paint!? To this end should I heat in some way the gel coat (with a paint stripper gun or oven bake) to force them to the surface and sand and fill before paint?

Also when I sand down filler and get very small holes left do I need to use putty or will a spray filler/primer do the trick?

 

[TAZ]

What I could do is get the obvious air pocket and dig them out and fill them. Then prep the rest of the glass, prime it. GUIDE COAT it (important!). Then sit it out in the hot sun and then sand it and see if you have any more bubbles.
As far as pits in the bondo, blow the surface VERY good as this may expose even more, then I use 3M flowable putty (3M #5824). Sometimes I'll cover the complete area, sometimes I take a razor blade and smear it in each pit if there are not many.
When you blow the surface, even if there appears to be a bubble, but it does not break open, go ahead and either blow it open or pick it open so you can fill it with flowable putty (or comparable putty. Not NitroStan as this shrinks too bad and has no hardener in it)

 

[TAZ]

What I could do is get the obvious air pocket and dig them out and fill them. Then prep the rest of the glass, prime it. GUIDE COAT it (important!). Then sit it out in the hot sun and then sand it and see if you have any more bubbles.
As far as pits in the bondo, blow the surface VERY good as this may expose even more, then I use 3M flowable putty (3M #5824). Sometimes I'll cover the complete area, sometimes I take a razor blade and smear it in each pit if there are not many.
When you blow the surface, even if there appears to be a bubble, but it does not break open, go ahead and either blow it open or pick it open so you can fill it with flowable putty (or comparable putty. Not NitroStan as this shrinks too bad and has no hardener in it)

 

[clivesroadster]

What do you mean by 'blow the surface'? I may be being thick or may be different terminology as I'm based in the UK. I take it a two pack putty (one with a seperate hardener) is always best to use?

 

[TAZ]

Basically what I meant was to take your blower and blow about 60lbs of pressure close to the surface. This will help break open any air pockets.
Then you can take some 2 part putty and fill these holes. THEN you can prime

 

[TAZ]

Basically what I meant was to take your blower and blow about 60lbs of pressure close to the surface. This will help break open any air pockets.
Then you can take some 2 part putty and fill these holes. THEN you can prime

 

[clivesroadster]

Thank you Taz, much appreciated. I will post photos when I get done.

 

[clivesroadster]

Well I'm getting on, just slowly! I have a question....how thick will the primer,paint and clear be? I know this might be a difficult question to answer but I am gapping the panels and could do with an idea.I'm not sure which colour blue yet but it will be one of these two: Blu Scuro Mic. 2CT PPG157086 or Blu Spark Met. (Chiaro Blu) 2CT PPG154922. I don't know anything about paint but hear these will both require a black base coat? does that mean a black coat of paint or a primer? Also what size nozzle would I use for spraying primer,paint and clear? Can I buy one gun and three nozzle? One last thing, does a fibreglass car need a specific primer and what is used to guide coat, a black paint or primer?

 

[TAZ]

As long as you have stock gaps, it should be fine (normally around 1/4")

You can prime with any primer (or any color), and then just apply a guide coat.

As far as the black basecoat, you might want to spray a coat or two of black sealer. Then a coat or two of black basecoat before applying the blue paint (must be a darker blue)

As far as a gun setup. You can use a 1.5+ for the primer. I 1.3 or 1.4 for base, and a 1.4 for the clearcoat.

 

[clivesroadster]

Your right Taz it's a dark blue, probably this one 1998 Lamborghini Diablo Walk Around Naples Motorsports - YouTube

 

[TAZ]

Nice color! Looks like Honda (motorcycle) Illusion Blue except the Illusion Blue turns to a purplish color at different angles.

Sharp!