|
|
26-07-2011, 06:29
|
#1
|
Registered User
Join Date: Nov 2010
Location: Heath, TX
Boat: 1978 Pearson 26 One Design
Posts: 316
|
Gel Coat Advice
I can't get the gel coat to cover the boo boo. I've patched the bow where the previous owner smacked the dock. The guy at west marine told me to use the neutral gel coat paste and mix the yellow tint to result in a basic yellow color. Problem is it's opaque and doesn't cover well. The color is decent but after 4 brush coats with sanding in between...it ain't cover'n worth a damn. I'm thinking I'll just get some yellow Brightside paint and be done with it. Or should I use the white gel paste and continue trying?
|
|
|
26-07-2011, 06:38
|
#2
|
Moderator Emeritus
Join Date: Jul 2010
Location: Key West & Sarasota
Boat: Cal 28 "Happy Days"
Posts: 4,210
|
Re: Gel Coat Help Advice
You are sanding too much off!
Feather the repair out over a wider area and build the gel up over the raw glass
__________________
Any fool with a big enough checkbook can BUY a boat; it takes a SPECIAL type of fool to build his own! -Capngeo
|
|
|
26-07-2011, 07:41
|
#3
|
Marine Service Provider
Join Date: Oct 2008
Location: Florida
Posts: 39
|
Re: Gel Coat Help Advice
Its helps to take a hatch/sample to a supplier and have a qt of gelcoat mixed to the original color
Kent
|
|
|
26-07-2011, 09:20
|
#4
|
Resin Head
Join Date: Aug 2007
Location: Seattle WA
Boat: Nauticat
Posts: 7,205
|
Re: Gel Coat Help Advice
What you are trying to do is an art form it took me years to perfect. Color matching aside, you need to spray the gelcoat not brush it. By the time you've sanded out the brushmarks. there's nothing left. Try a preval disposable sprayer. Spray 3-4 coats about ten minutes apart. Prep well and make sure you use a surface seal in the last coat. Use real gelcoat instead of the west marine patch kit. Shelf life for gel is one year, most patch kits have been on the shelf much longer.Good luck!
|
|
|
26-07-2011, 09:49
|
#5
|
Registered User
Join Date: Nov 2010
Location: Heath, TX
Boat: 1978 Pearson 26 One Design
Posts: 316
|
Re: Gel Coat Help Advice
So I understand...do not use paste...instead use gel coat? With our without wax? And spray it.
|
|
|
26-07-2011, 10:06
|
#6
|
Resin Head
Join Date: Aug 2007
Location: Seattle WA
Boat: Nauticat
Posts: 7,205
|
Re: Gel Coat Help Advice
Quote:
Originally Posted by rhr1956
So I understand...do not use paste...instead use gel coat? With our without wax? And spray it.
|
Yes, fair it out and then spray gelcoat. Add wax in the last coat or finish with a coat of PVA. Spray the first coat over just the repair and each successive coat slightly larger. You can get a preval at home depot. Buy several, they are cheap. Heat the preval with a heat gun in-between coats and it'll spray better. Hot water immersion works too if you don't have a heat gun. Don't heat the gelcoat though, just the spray canister. Finish with 600 wet then 800 wet. Then polish with 3M super duty. If your color match and prep work is good it'll look like new. However, your color match almost certainly will not be good...
|
|
|
26-07-2011, 10:23
|
#7
|
Registered User
Join Date: Mar 2007
Location: Santa Cruz
Boat: SAnta Cruz 27
Posts: 6,683
|
Re: Gel Coat Help Advice
I would stay away from the West Marine brand gelcoat with wax. I tried some the other week and as soon as you added a little catalyst the whole batch turned into a gooey ball within seconds. I tried as little as 1% catalyst and the same thing happened--took the can back to the store for a refund.
|
|
|
26-07-2011, 10:51
|
#8
|
Eternal Member
Join Date: Mar 2008
Location: Tarpon Springs FL
Boat: Cabo Rico 38
Posts: 1,987
|
Re: Gel Coat Help Advice
I'd go along with minaret's advice. He's right about one other thing, matching gelcoat color is an art. Sometimes I get lucky and hit it in 15 min and other days it can take more than an hour to get a perfect match. There are a number of tips and tricks but I will guarantee you that if you match to the existing oxidized gel color, it won't match in a couple of weeks. Light color gelcoat will age darker and dark color gelcoat will age lighter. You won't really know (unless you are a pro like minaret) how close your match is until after the gel has been out in the sun for a week or three.
I always find a spot that I sand and buff until I've exposed like new gelcoat and use that as my palette. I try to do it in the shade and make sure I've had any sun glasses off for at least 30 min. I also thin the devil out of the new gelcoat I'm mixing to be sure that any pigment totally dissolves. Then it is trial and error until when I smear a bit of new gelcoat on the palette and can't see ANY difference. If you decide to go this route, take it very slow because a little pigment can go a long way. On my boat it takes about 6-8 drops of pigment per quart to match.
Also, since you are not adding any catalyst, the gelcoat won't harden and you can clean your palette from time to time with a rag and a bit of acetone.
Rich
|
|
|
26-07-2011, 11:01
|
#9
|
Registered User
Join Date: Nov 2010
Location: Heath, TX
Boat: 1978 Pearson 26 One Design
Posts: 316
|
Re: Gel Coat Advice
OK, I picked up a couple of the Preval Sprayers. I'm guessing I should have bought 5 or 6 of them. Seems to me it's going to be a one shot deal between coats, requiring a new sprayer for each coat due to gel coat setting up in the unit. Am I right about that or am I missing something? Also, should I get white gel coat or stick with the neutral? Finally...I was playing around with an online color palette tool and when I used a white base with two parts yellow to one part red, I got what looked like a close match to my yellow target color. Any suggestions regarding tint colors to use to result in various yellow shades?
|
|
|
26-07-2011, 21:06
|
#10
|
Resin Head
Join Date: Aug 2007
Location: Seattle WA
Boat: Nauticat
Posts: 7,205
|
Re: Gel Coat Help Advice
Quote:
Originally Posted by cabo_sailor
I'd go along with minaret's advice. He's right about one other thing, matching gelcoat color is an art. Sometimes I get lucky and hit it in 15 min and other days it can take more than an hour to get a perfect match. There are a number of tips and tricks but I will guarantee you that if you match to the existing oxidized gel color, it won't match in a couple of weeks. Light color gelcoat will age darker and dark color gelcoat will age lighter. You won't really know (unless you are a pro like minaret) how close your match is until after the gel has been out in the sun for a week or three.
I always find a spot that I sand and buff until I've exposed like new gelcoat and use that as my palette. I try to do it in the shade and make sure I've had any sun glasses off for at least 30 min. I also thin the devil out of the new gelcoat I'm mixing to be sure that any pigment totally dissolves. Then it is trial and error until when I smear a bit of new gelcoat on the palette and can't see ANY difference. If you decide to go this route, take it very slow because a little pigment can go a long way. On my boat it takes about 6-8 drops of pigment per quart to match.
Also, since you are not adding any catalyst, the gelcoat won't harden and you can clean your palette from time to time with a rag and a bit of acetone.
Rich
|
Ah, a fellow sailor who knows something about color matching. Here is my secret tip. Prep and polish a spot as described by cabo. Make it a spot near the repair, a color can very dramatically from bow to stern due to less than perfect mix in the drum at the factory. You are trying to restore the original color so you can match to it. Sometimes you can find the inside of a hatch or something which has not been exposed to weather and that can help. Once you have selected and prepared your spot, acquire a piece of clear mylar film. Cut it into one inch squares. In a pinch cigarette cellophane works fine. Put a daub of prospective color match onto your prepped area. Then take a square of the mylar and lick one corner to get some spit on it. Put the dry corner onto your daub of gell. You will see a clear demarcation line between the spit and the gell. Gently rub the mylar until the spit line touches the gelcoat. You will be able to see even the smallest color difference using this technique. I can't explain why it works, but iff you try it you will see why this is the deepest darkest secret of the color matchers art. With practice anyone can match better than any spectrograph.
I rescued a 28' San Juan adrift with no power in 25 knots off Lagoon point, Whidbey Island, in between typing paragraphs on this post. Smartphones are awesome!
|
|
|
27-07-2011, 06:21
|
#11
|
Registered User
Join Date: Nov 2010
Location: Heath, TX
Boat: 1978 Pearson 26 One Design
Posts: 316
|
Re: Gel Coat Advice
Update! I took the advice from Minaret on the Pre-Val sprayer. Worked great except for my color match. I learned that one drop too many of tint will wreck the effort. I played around with an online color chart and learned that some red will bring down the harshness of the yellow. My boat's yellow color is obtained by using a lot of yellow tint and a tiny bit of red. I put three drops of red. Should have stopped at two. Will re-do tonight and hope for some improvement. Thanks again for the advice Minaret.
|
|
|
27-07-2011, 08:46
|
#12
|
Resin Head
Join Date: Aug 2007
Location: Seattle WA
Boat: Nauticat
Posts: 7,205
|
Re: Gel Coat Advice
No prob, happy it's working out for you. Stick to it and you'll get it. Try using yellow umber and burnt sienna. These along with a little bright yellow, red, and black, are the usual suspects for getting most shades of white. Be careful with the red and black. Both generally need less than a drop. I generally use a sliver broken off a stir stick for getting a micro drop. Almost all whites need a hint of black. Good luck!
|
|
|
27-07-2011, 08:59
|
#13
|
Registered User
Join Date: Nov 2010
Location: Heath, TX
Boat: 1978 Pearson 26 One Design
Posts: 316
|
Re: Gel Coat Advice
At West Marine they only had basic tint's red, yellow, black etc. Where would I get the umber and sienna type tints?
|
|
|
27-07-2011, 09:08
|
#14
|
Resin Head
Join Date: Aug 2007
Location: Seattle WA
Boat: Nauticat
Posts: 7,205
|
Re: Gel Coat Advice
We get gel tints from Fiberlay in our area. You can also use Universal tints but I like to stick with tints designed for gel. Order from Fiberlay or find a local source. Or you might be able to just make it work with what you have. Try the mylar/cellophane trick. Just think, by the time you get it right, you'll be ready to do all your own gel repairs!
|
|
|
29-08-2011, 12:07
|
#15
|
Registered User
Join Date: May 2011
Location: Portland, OR, USA
Boat: Hallberg Rassy 35'
Posts: 1,200
|
Re: Gel Coat Advice
Quote:
Originally Posted by rhr1956
At West Marine they only had basic tint's red, yellow, black etc. Where would I get the umber and sienna type tints?
|
I've had really good luck with TAP Plastics. The products are good and fresh and the staff are very helpful.
|
|
|
|
|
Thread Tools |
Search this Thread |
|
|
Display Modes |
Rate This Thread |
Linear Mode
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
Advertise Here
Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
Vendor Spotlight |
|
|
|