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Moderator4
11-10-2008, 11:47 AM
I have a friend that has a family fun boat, not a MC, and he has some big scratches in the hull, he wants to repair them, but I know nothing about gel coat repair. where can one find gel coat repair kits? and can you get them in colors? how can you get color match? he has black and a light cream or coffee colored hull.

Any information would be helpful.

Thanks in advance.

flipper
11-10-2008, 11:52 AM
Overtons and West Marine has them. You have to mix the color yourself, smear it on, let it dry, and sand it down.

erkoehler
11-10-2008, 11:56 AM
Spectrum Color will probably have a direct match color. They do make a patch paste kit to fix scratches that comes in a variety of colors.

Moderator4
11-10-2008, 12:02 PM
Is spectrum color a brand name?

erkoehler
11-10-2008, 12:12 PM
Yes....... http://www.spectrumcolor.com/

Skipper
11-21-2008, 12:53 PM
I thought the mods knew everything?

Write down your hull number first. Then call MC and get your Spectrum color numbers. Then call Spectrum. You'll probably need the tint adjust kit to get the color just right.

ttu
11-21-2008, 12:56 PM
I thought the mods knew everything?

Write down your hull number first. Then call MC and get your Spectrum color numbers. Then call Spectrum. You'll probably need the tint adjust kit to get the color just right.


skip, he said his friends boat is not a mc. i bought some from spectrum to fix a bo bo when i had a sc boat and the match was perfect.

Skipper
11-21-2008, 01:20 PM
What a dork! Sorry...

Still, Mods are supposed to know everything.

Edit:
Write down your friends hull number first. Call the boat company and get the Spectrum color numbers. Then call Spectrum. You may or may not need the tint adjust kit to get the color just right.

bigmac
11-21-2008, 01:34 PM
This thread was very helpful to me, though. I have a little gouge on my swim platform from my hydrofoil. Spectrum sent me a jar of Sunrise Yellow gelcoat repair paste for $25. Much better concept than those mix n' match repair kits that Overton's sells.

corey
11-21-2008, 02:12 PM
The patch paste kits work great just make sure he reads the directions. The kits are basically colored body filler and not paint so don't prefill the scratches.

TOO-TALL
12-25-2008, 02:22 AM
Thanks for this post.And the Link
I have a nick under my platform it sounds like the Patch Paste Kit is what I need.

CameronCarey
12-26-2008, 12:46 AM
Those paste kits are ok for a non cosmetic repair........here's my two cents..

.....the typical repair kit version you can buy at boaters world ect made by evercoat has a few ounces of gelcoat and some colors to tint it.....this is not enough if you have never done a gelcoat repair before....here is my generic suggestion for gelcoat repair..

There are two equally impossible tasks to gelcoat repair

1) matching your color
2) getting it to harden.

we can avoid these challenges if you are repairing something below the waterline or in an inconspicuous area of a white boat.

if the area to be repaired is
1) White
2) in an inconspicuous area...use white marine tex instead.......its much easier to work with and will give an amateur a better result with less frustration.

Think of Marine Tex as boat bondo except .......it may be the strongest thing on the whole damn planet...its a two part mixture a base and a catalyst, and its very difficult to mess up..
.......the downside is that the repair will be flat white.. (you can buy marine tex at any boat store)

if you don't meet the marine tex criteria here is your shopping list at your local nationwide boat supply chain

Evercoat Gelcoat (clear if you need an opaque color like black or dark red.....if its something that's pastel......get a white base gel coat.)......if you have never done this get a quart!
PVA mold release also made by evercoat
Dixie cups made by dixie
Mixing sticks or popsickle sticks...........i just buy the pop sickles and clean them myself
extra hardener
coloring agent (small tube of stuff)
a syringe from your local drug store
cardboard, wax paper and blue masking tape (you will use this as a mold of sorts)

otherwise you get to go on the adventure of matching gel coat...buy regular gel coat in the pint size or quart size container...............

A note about brands

There is not a user perceivable difference in quality between ever coat and one of the ultra high end gel coats.........at least not from a repair prospective......just make sure the can you buy hasn't been sitting on a shelf for 5 years......there is usually a date code somewhere on the can..

Step one........figure out how to match your color.

fill the dixie cup up to one of the lines with gelcoat, maybe 3/4 inch deep......note which line you filled it to .........as it will likely take several tries to match your color

Use the syringe to measure out the coloring agent to get what you think its the right color

add a few drops of hardener stir the mix up with a mixing stick , and pour a nice line out on a piece of that scrap cardboard we had on the list.....once it dries compare it to your boats color........repeat and refine until you have a good idea what the mix is

Once you know what your color mix is you get to do the real deal

Step two fix the damaged gell coat.

but first 5 things you must know/do

1) The stresses (force/area) applied to gel coat repairs must be minimized else your repair will pop out or crack......the way we minimize these stresses is to distribute the force on the repaired area over the largest area practical............this is accomplished by "Scarfing out" the area to be repaired (so you need to sand a gentle sloping transition into your damaged area such that we have no sharp edges)

2) ideally we would have a nice chemical bond and all the polymers that make up our gelcoat would be commingling.........that's not going to happen with our repair so the next best thing is a good mechanical bond...........there is only one criteria for a mechanical bond to work involving gelcoat...........the gelcoat must have the ability to wet the surface.......meaning all impurities have been removed.......i typically use some scott shoptowels and acetone and wipe the repair area several times to insure that no oil/dirt/dust/whatever is on the repair area.

3) as mentioned earlier gelcoat does not dry as well as we might hope, all the time. To compensate for this we use a catalist called PVA mold release. even if there is no mold PVA mold release sprayed (from a windex type bottle) will improve the curing habits of gelcoat.

4) gelcoat (and fiberglass resin for that matter) does not cure well below 50 degrees F... so if your in a climate where your relying upon nature to heat your gelcoat.....do the repiar in the morning so it can heat up all day and dry.

5) Dried is not cured, gel coat my dry in as short as 5 minutes if you do everything correctly and the environment is warm enough......it takes about 30 days to cure......so its best to do the repiar and let it sit for a month before you comeback and wetsand/compound the repair to it in nicely with the undamaged gelcoat around it.


With the above mentioned here is how i fix a scratch/gounge in gelcoat

scarf the repair such that i have at least .3 inch long transition into the repaired region, if the gouge has removed fiberglass beyond the gelcoat........fill this in with marine tex.

clean the area thoroughly with acetone, clean the area 6" around the repair also as we will need to stick some tape to those areas......and any wax may keep that from happening

prepare a peice of cardboard an inch or two larger than your repare to act as a "Caul" plate......this will hold the gelcoat into your repaired area and minimize sanding later.

Cut out a pieces of wax paper to match your piece of cardboard....

mix up the gel coat which you have pre determined the mixture and color of.

use a new cheap paint brush to "Paint" the gelcoat over the repaired area

spray pva mold release over the gelcoat you have distributed on the repair.

place your piece of cardboard protected by the wax paper over the repair and tape it down with the blue tape, (some folks get tricky and use other things as a caul plate, teflon plate works great)

walk away once you are satisfied that everything is taped down,

wait about two hours and remove the cardboard/wax paper mix

spray the area again with PVA mold release and let it sit.

ideally you would let the repair sit for 30 days.........in warm climates you may be able to start sanding, buffing the area in as little as a day....i have no rule of thumb here.....

after the repair is cured or at least really dry wet sand or compound the repair to level it with the surrounding gelcoat.

then apply a good wax (3M makes alot of great products) over the entire area.


Good Luck

Thrall
03-02-2009, 07:36 PM
CameronCarey. Thanks for the good write up. I'm going to repair a substantial scratch in the side of my hull and have a couple questions. Having done a fair amount of auto body, I would think that extending the gel beyond the immediate repair would be better for blending the color (which without ALOT of different mixes would be difficult on a 13 y/o boat).
The scratch is long and narrow and down to the 'glass in most areas.
Never having worked with gelcoat before. If I used the patch paste and just filled the scratched area (after prep of course) would there be any physical line between the new and old gel? (Not just color, but will it fill "perfectly" after sanding?)
If I sprayed on new gel, what is req'd?
Does it run thru a normal siphon feed or HVLP gun?
Is it as easy as blending single stage paint (scuff, spray, sand)?
How fast does gel coat build thickness? If the scratch is 1/8" deep will it take like 20 coats, or should I fill it a bit with marine tex first?

ALot of questions, I know, but I'd rather do this one time than trial and error. Thanks

StAustin15
05-06-2009, 03:32 PM
I thought that these videos were a fairly good place to start.

http://www.youtube.com/watch?v=iWEE6SFUdpg

http://www.youtube.com/watch?v=en-8SbhdF_k&feature=related

jdl xstar
06-29-2009, 10:20 AM
I applied some spectrum gel goat repair to a small ding and I sanded it out and need to polish it. My question is...Can the same polishing compound that is used on cars be used on a boat? The spectrum kit directions doesn't specify "marine" polishing compound so I am inclined to use what i have which is just your regular car polishing compound. :confused:

bigmac
06-29-2009, 10:59 AM
I started with 300 and worked up to 1600 grit, then just rubbed my repair down with polishing compound, then some cleaner/wax.

jdl xstar
06-29-2009, 11:13 AM
Where are you buying 1000+ grit? At home depot, the highest i saw was 600.

babymoore3
07-02-2009, 10:49 PM
Usually Autozone, Advanced Auto, Oreilly's, NAPA and sometimes even Walmart will carry fine grit sand paper. Keep it wet!

bigmac
07-02-2009, 11:38 PM
Where are you buying 1000+ grit? At home depot, the highest i saw was 600.Local TruValue.

Thrall
07-21-2009, 08:21 PM
I applied some spectrum gel goat repair to a small ding and I sanded it out and need to polish it. My question is...Can the same polishing compound that is used on cars be used on a boat? The spectrum kit directions doesn't specify "marine" polishing compound so I am inclined to use what i have which is just your regular car polishing compound. :confused:

You can use automotive rubbing and polishing compound. I've found 3M products, compounds and pads, to be the best.

BTW, I got my repair done. Went relatively smooth.
I found that you need to have sharp edges around the repair. Feathering out the gel does not work. It needs to be relatively thick to cure and bond.
I ground everything nice and square with a die grinder, used a util knife to square up the edges that feathered out with the grinder (man that stuff's hard to cut!).
Filled the deeper scratch with bondo and ground it back down a bit.
1st time I mixed an ounce of gel. Color came out perfectly, but I didn't get the right "build up" dabbing it on with a brush. Lots of low spots or pits after I sanded it down.
Took it down again, this time only mixed 1/4 oz. Must have had 1 too many (or not enough) drops of catalyst or curing agent, because the color is a little darker.
This time, I sprayed a little PVA mold release on it just as it was starting to set up and put a piece of wax paper over it and smoothed out the gel with a bondo spreader. Looks good after sanding and polishing, just ever so slightly darker.
FWIW, I wet sanded it down about 30 min after application, put some PVA and paper over again to cure for the night, polished out the next day.