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  #1  
Old 25th September 2012, 10:56 PM
baz-r baz-r is offline
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Default holes all over her body

i got holes there multiplying and im lousing control (to grease theme tune)
seriously no joking i got problems with me grp gel cracking off to find voids to the matting underneath its realy getting me down
most popped up after i had to remove most of the body and put out in the garden under the heat of the sun had made the trapped air bubbles expand.
also have some other minor refinishing to do

now i need to know the best way to repair it. i know i will need some gel in black (dont know code) and light blue (bs18E50) what else will i need and how do i go about fixing it? also where can i buy small amounts of gel from i need to do the job

i also have some DA sander marks in places of the black polished finish and a few odd marks i think the best way to fix this would to flat it of with a block ,some soapy water and very fine wet and dry then polish it back with somthing.
what is the best option to polish the dull matt finish out after do i use normal auto paint products or somthing else?
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Old 26th September 2012, 09:05 AM
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That's awkward and unusual Baz, I dont have your address anymore so if you want to pm me then i will put together a package of medium and fine cut buffing compound (easily take out any swirl marks) and some gel with catalyst.
Any more concerns Baz feel free to e-mail me some pics: andrew.hugill@ntlworld.com and we'll sort them out.
Take Care...............Andrew
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Old 26th September 2012, 11:34 AM
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When mounting the rear arches I accidentally shone a flashlight through one, and saw lots of bubbles in the gel coat, too...
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  #4  
Old 26th September 2012, 05:01 PM
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Wynand Wynand is offline
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Quote:
i got problems with me grp gel cracking off to find voids to the matting underneath its realy getting me down
Quote:
When mounting the rear arches I accidentally shone a flashlight through one, and saw lots of bubbles in the gel coat, too...
Shabby workmanship from the laminator and not excusable Lost a lot of money with my GRP work and boat moldings because the laminators taking short cuts and had similar type rejects...
These faults usually happens when the operator tries to laminates 2 or more layers at one go causing the bottom layer to be left partly dry, or to thick CSM grade as a surface layer against the gel. Most commonly caused by not rolling out the wet laminate out with ribbed rollers and using brushes only.

Depends how you want to have it fixed. If you want a gelcoat finish there is one way and if you are to paint the parts another way. But first, take a 10mm round bar and round off the one end smoothly but pointy (about 150mm long). Start tapping away over the complete surface of the molding you have and as soon as you find another bubble(s) it will sound hollow or the gelcoat will crack away. When you are sure their are no hidden bubbles, take a sharp object and start peeling the gelcoat off until you get to a solidly bounded gel again.
Be warned, some of these bubble gelcoat will peel away to quite a large area although it did not sound hollow when tapped. When you are done removing all the loose gel coat, time to repair.

If you are going to paint: Mix some micro balloon spheres (or "kulu" powder) into some general purpose laminating resin until you have a nice textured paste much like the viscosity of toothpaste. Clean all the areas to be fixed with acetone or styrene. Take a flat scraper and fill the holes but make sure you apply plenty pressure for a good bond. Fill until damage area is slightly higher than the surface - dont forget to add MEKP (hardener) to the mix and mix small quantities at a time to limit waste should it gels on you whilst busy.
When done, sand down. I prefer 120# grit dry AbraMat - aluminum oxide - sanding strips which I stick onto a flat plank (handle on) with velcro backing fitted to roughen excess filler off. Then start with 320# grit water sand paper and finish down till 1000# grit.
Prime and paint with 2K or similar 2 pack paints.

If you want gelcoat finish; Preparation much the same as above and fill the holes partly with filler to leave little space for gelcoat if it is deep - if the area is shallow, apply gelcoat directly to area. Do not apply gelcoat thicker say than 2mm because although it will cure, styrene is trapped and will over time evaporate to the surface causing discoloration and the common cracks found in older grp parts which is a direct result of to thick a gelcoat.
BUT, gelcoat is un-waxed and need some liquid wax to be added for it to cure.
If you do not have liquid wax, dont panic. Apply the gelcoat (remember the hardener) straight out of the tin so it sits a bit higher than the surface. Cover the gelcoat with a piece of wide (40 - 50mm) Cellotape or brown box tape. The purpose of this is the same as the liquid wax - to remove oxygen from the gelcoat to be able to harden. If you have PVA mold release (red stuff), just smear some of that over the gelcoat for the same result and when the gel is cured, simply wash off the PVA with water.
Sand down. If you still have some spots and hollows after gel is sanded smooth, simply repeat the step but remember to clean the area with acetone or styrene before applying more gelcoat or filler.

My only problem with gelcoat repair is the fact that the areas will be visible if the colour matching of the gel is not 110%...

Hope this will help
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Old 26th September 2012, 07:06 PM
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The guy thats paints my cars for me always puts them in an oven first for a good baking. He then digs out all the pop marks and syringes in the gook to fill up the holes,then pokes it in the oven again. Its only when he is happy that its all settled will he start on the paint. Shit fibreglass has cost him in the past. Rob Bud of eagle cars had a laminator, he was the only guy that rob would let anywhere near the body molds. He reckoned he had seen lots of guys come and go but no one had the 100% record this guy had.

Edit. Its a highly skilled job and not something you can get muckers just to help with.

Bob
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Last edited by robo : 26th September 2012 at 07:20 PM.
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  #6  
Old 30th September 2012, 11:03 PM
Cyberbeej Cyberbeej is offline
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Default CKC Magazine

John dickens does a good book and dvd in complete kitcar magazine.
I bought them on there web page. Very informative and he shows you how to repair gel coat bubbles like your experiencing.
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  #7  
Old 6th October 2012, 01:30 PM
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equinox equinox is offline
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I am not in the habit of commenting on the forum but thought these comments might help.
Gel cracking
This sounds like de-lamination which is different to air bubbles.
De-lamination can be caused by a couple of things; the most common is the gel coat left in the mould too long before being laminated, the other common one is a dry lay-up. There are also other less common problems; however both of the problems are generally operator error.
A dry-layup
A general rule of thumb to go by when using 450g chop strand mat is to use 1kg of resin per 1 square meter, when using 600g CSM you would use 1.2kg per meter. Gel coat would be 500g per 1 square meter.
Gel coat repair
Gel coat repair is not easy and not always successful; the problem with gel repairs is that the gel will exotherm causing very small holes on the surface. These over time will collect dirt and grime, thus giving you the discolouration. If these repairs are small, say no larger than 6mm area on a radius or in an area hidden then you would get away with it. Lighter the colour less chance of seeing the repair (black forget it).
Repairing for painting
I would recommend just standard Upol car body filler, this is polyester based filler easy to work with and easy to obtain.
In my eyes; oven baking after spraying is a big NO NO, I have always argued this with car sprayers. Polyester is a form of plastic at the end of the day. Would you put a plastic item in your oven at home ramp the heat up and expect it to survive?
Polyester will take heats of about 60 degrees for a very short time, gel coat about 80 degrees.
Not only will you distort the item you will cause any air, no matter how small, to expand and ruin the surface of your panel.
If you must bake your paints off then the temperature must be no higher than 30-35. All post curing can be done at lower temperatures it just takes longer.
Air bubbles
Yes, a lot are caused by operator error but not all can be helped. If you back up your laminate with colour to help give you a strong colour finish on your surface, you become blind to any air that may be trapped between layers and yes, a good experienced laminator would work methodically to ensure this did not happen; but sometimes it does.
Also note that CSM can hold fine air bubbles between the strands.
Fibreglass
In my 30 years’ experience in this trade I have seen patterns, moulds and items go wrong for no apparent reason. You just sometimes have to accept expectations of perfect are not always possible.
In any trade if you see a lot of items for sale cheaper marked as substandard or seconds on a regular basis, you have to question the ability of the manufacturer.
Training
I see Talon Motor says you can get a day’s training for £150-£200 to learn how to do it properly.
If anyone wants to spend a day getting an idea on how to produce items made in fibreglass then give me a call and spend the day at my factory free. You will go home at the end of it with a little bit more of an understanding but not as a skilled laminator.

I have always believed that when you buy something you should get value for money.
You won’t get a Rolex from a Sunday market.

I hope Baz-r, that this might help with the repairs of your body work.
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  #8  
Old 6th October 2012, 09:58 PM
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equinox equinox is offline
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Quote:
Originally Posted by Talonmotorsport View Post
Thats a great offer I'll give you a call in around 3 weeks when I have all my plugs painted and polished so I can learn how to make the moulds correctly and get a better understanding of how it should be done.
You are more than welcome
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