Getting Started With Gell Coat

[Grant_West]

Hey Im about to get into fixing some gell coat on my boat.

What information can you share . I have a small chip I need to have filled and I want to repair or touch up the holes I filled in the back of the boat where I removed the Pedo tube's

Is there a how to gell website or section

Where can I pick up the Color I need I have Patriot Red

Thanks Grant

[mf01]

I can tell you about my experience.

I had a dime sized chip under the boat near the side. I bought a gel coat repair kit from Spectrum color. You can go in and select the year an color for your boat on their website. I put it on last Saturday. It seemed to match well, but I'll see this weekend after drying (in storage). I did notice that it didn't fill in the chip completely. I talked to Spectrum and they said you can do a second coat. I plan to do it this weekend. Afterward it has cured, you're supposed to wet sand it to smooth it out.
'

[WakeSlayer]

DavidF should be along at some point. He has done some pretty involved gel work.

[core-rider]

http://www.spectrumcolor.com/

Like mf01 said, go to Spectrum color and you can give the info you need to order the correct factory color gelcoat. They also have a bunch of how-to articles in their technical info page that should explain everything you need to know. Between your work with carbon fiber and body filler you pretty much have all the know how you need.

[vettekid]

Gelcoat Repair

I finished my first repair last summer. There are some very good how to videos on you tube. I just searched for gelcoat repair.

[Quinner]

RE: Gelcoat Repair

Uh Oh, better call Maaco!

[bchesley]

RE: Gelcoat Repair

I have watched a friend do numerous repairs of chips and holes. He is a Correct Craft trained repair guy so I trust him completely. He will grind the are of repair out to get to clean gel cote and clean fiberglass. Then he will use the premixed past that correct craft sells. He says to get to clean gel to keep from getting a ring around the repair. After the repair cures just sand, buff, and polish.

[Grant_West]

I orderd the gell stuff from Spectrum. Thank's for the link . I got the paste style stuff. Like I said I have a few holes to fill/patch and a chip on he deck. How close do you think the color is gonna match? The chip is on my deck. So it get's lot's of sunlight when out on the water. My boat dosen't seem to have faded so im not real worried. I have removed stickers or traction pads from the top deck where sun has never hit the underside and the color looks pretty much the same so Im not worried about trying to match a faded color.

The You tube video's seem pretty straight forward thanks. I guess I can start at the back of the boat under the swim deck and learn, then when I have it down pretty good I can move to the deck.

How much does the gell shrink??? How much should you try and leave on top to account for shrinkage. I was thinking about trying the film tequnique after brushing it on.

It seem's like when you apply the film and squee-gee the film your pushing all the gell away and making it thinner by the repair

[bchesley]

You can build a small wall of tape around your repair to add a little more to it to fight any shrinkage.

[mcbridek]

Grant_West - if you search this forum for gel coat repair, you will find some excellent detailed write-ups that explain the sanding and finishing process. I used these last winter and they were very helpfull. I was my first time doing repairs and the results were very good.

[DavidF]

Ok, I'm here. Mostly good advice so far from others. Small chip repair is very easy, so don't worry and go for it. If you make a mistake, you can do it again and again. Basically do this:

1. Get color matched gelcoat. Paste is fine, or not, it does not matter...they are essentially both the same composition.
2. Yes, sand out the chip well with course sand paper, you want to get new/clean gelcoat all around the repair area. Avoid sanding the good gelcoat adjacent to the chip as much as possible. Clean the area well with acetone before proceeding. Acetone will not harm cured gelcoat. Acetone will disolve uncured gelcoat, but should NEVER be used as a gel thinner (it breaks it down). Use Styrene to thin gelcoat.
3. Add MEPK (catalyst) to the gelcoat and using whatever is handy...brush, popsicle stick, whatever, fill the hole or chip. Make sure the new gelcoat is well above the adajacent surface.
4. Using clear packing tape, light cover the repair with the tape. Do not flatten or smooth out the tape other than to get the air out as mush as possible. You goal is to leave the new gelcoat proud of the original surface. Do not worry how it looks at this stage as you will be sanding it smooth. It is easy to sand it flat later, so leave it high. The tape seals out the air and allows the gel to cure mostly tack free.
5. Once the gel has cured, remove the tape and sand smooth by:
a. Spray a light mist coat of black paint on the repair and surrounding orginal surface.
b. Using 220 grit paper wrapped around a small block of wood...say 1.5" wide, sand the repair down just until you get to the marker paint. Avoid heavey 220 grit scratches in the adajacent surface or you will have to sand more to get them out.
c. Trace (paint) again and go to 320 or so paper.
d. Trace again and go to 400 wet paper. Sand off all tracer paint around the repair. See you repair should be now invisible and level with the adjacent surfaces.
e. No more tracer, but swith to 600 grit wet, then work you way up to 1200 or finer before compounding and polishing.

Avoid flat spoting the area if the repair is on a curved surface. Sand with the curve. Change sanding directions often. Go easy with the sand paper. The origina gel is very thick, so you will not sand through. Avoid over catalyzing the gelcoat, or it will boil and leave air bubbles when cured. If I remember correctly, it only takes 3-4 drops of MEPK per ounce of gelcoat. Remember, gelcoat is simply polyester resin with pigments.

[DanielC]

Do the search on gel coat repair on this site.
If you can stand to wait, just leave the gel coat high, and unfinished for a while. let it shrink. Then sand and polish it down to contour a month or so later.
The patch paste work well, but if you just have liquid gel coat you can let it sit in an open container, with a paper towel, or cloth over it, and some of the solvents will evaporate out, and the gel coat will thicken up.

[DavidF]

Why wait a month. If you cover it with tape and leave it overnight, it will be ready to sand. If you do not cover with tape, the surface remains tacky indefinatley. You can wipe the tacky surface off with acetone and then start sanding. Normal gelcoat is thick enough to use right away. The tape will hold it in place. On vertical surface, I stick the tape below the repair area and fold it back. I then apply the gelcoat liberally and ok to let the tape catch any runs. I then roll the tape over the gel and seal all around the repair to lock out air. Next day, peel tape, wipe down with acetone, trace and sand.

[Grant_West]

I think what he is saying is the gell shrink's over time if you let it shrink then when you sand it flat a month later it will not shrink more and look like a dip.

yea I have time I dont need to repair it in One weekend. I think Ill do the holes in the back of the boat over the weekend. If it shrinks No Big Deal you will never see back there.

I have a LARGE heet lamp it says its best to work in 70-80 degree's Now does this mean
heet the garage and then keep it warm. While you are doing the work or for day's after the repair?

One more Question. The holes in the back. I filled them with a JB weld epoxy. Is it ok to put the gell directley over the epoxy. Or do I need to use some other filler that the gell will bond to. Should I recess the holes slightly so the gell can go into the void like repairing a crack/chip

[DanielC]

There are two processes that are going on when gel coat cures. A solvent (styrene) is evaporating, and the short molecules of a liquid are joining into long molecules, making a solid. In most cases, the gel coat gets solid before all the solvent has evaporated. As the solvent continues to evaporate, the solid will shrink.
In a shop, or at the dealer, they cannot afford to store your boat for a while, while the gel coat fully cures. They have to make a flat rate to remain profitable. Also more often than not, the customer wants his boat back a week ago.
On the JB weld, I would clean it with acetone, sand it with 80 to 120 grit sandpaper, Clean it with clean acetone again, and blow it off with clean air. Then apply the gelcoat.
Do not get the area too hot. Excessive heat may cause a color change, or other problems. Warm to the touch is fine. Remember, you are not trying to beat a flat rate, you want a good quality repair.
Take notes of every thing you do with the repair, that way you can make changes to your process, and do a better job next time.
No need to heat the whole garage, but if you want to, that is fine. Once the gel coat has become solid, you really do not need to heat it again. If you get a sunny day, park the boat where the sun can shine directly on the repair, if possible. A heater that blows warm air will also help the solvents evaporate, also.
Time to go work on a Hydrodyne I an doing a gelcoat repair on.