Hole in gel-coat

[1979 Quartermasters]

Hi Guys;

I have this damaged spot in the gel-coat in the hull. The PO must of run it ashore or hit a rock or something. I'm wondering how I might fix this. If its not to much to ask, I would like details, materials, tools and what ever I might need to attempt this repair in my shop. Thanks......

.....Ken

 

[oops!]

Re: Hole in gel-coat

wow 79....that is a big whack....

no worries.....that is easy.

mix some white gellcoat with cobosil...(you will have to color match the gellcoat by adding tint or pigment.)

(cat all gellcoat at 2% mekp)

scuff the area with 80 grit......clean with acetone.

take a paint brush.....and fill the area....let it tack off.....and add some straight gellcoat to a bondo spreader....then quick swipe over the area....this will fill all the brush marks with gellcoat....

let cure.....

start at 320 grit....and sand the area.....then 400....then work up to 1500 grit....and buff....including cure time.....3 hours.

 

[1979 Quartermasters]

Re: Hole in gel-coat

Some people are telling me I need to grind it back to where the delamition stops and a little more. I guess a little grinding wouldn't hurt, eh?.... Ken

 

[oops!]

Re: Hole in gel-coat

de lam isnt the problem.....

this is a whack....

the edges of the gellcoat are still bonded to the glass.....if you see an area that the gell is not bonded ...then yes....grind it....but dont go too far into the glass....

 

[tpenfield]

Re: Hole in gel-coat

Not too bad of a fix . . .

- Small tube of gelcoat or perhaps a gelcoat repair kit.
- 1 piece of plastic sheet (usually comes with a gelcoat repair kit)
- Duct tape
- 1200 grit wet/dry sand paper

The kit will have instructions on the finer points of the process. The plastic sheet goes over the gelcoat to give it a smooth finish that matches the shape of the hull.

 

[1979 Quartermasters]

Re: Hole in gel-coat

Well I'll see what I can find for a gelcoat repair kit and give it a try. Thanks.....

....Ken

 

[oops!]

Re: Hole in gel-coat

those little plastic sheets can really get you into trouble.....

most of the time.....they are pressed on the gellcoat...leaving a dip in the area...

the real reason they are there is because air inhibits the cure of the gell.....so when you put them on ....the gell cures tack free.

alot of people think they just put on the plastic sheet and then done....but it rarely works that way.

sanding and fairing is a way of life to a gellcoat repairer

 

[Searayb]

Re: Hole in gel-coat

I've used Evercoat Gel Coat patch, comes in different colors, you can buy it at Bass Pro.

 

[1979 Quartermasters]

Re: Hole in gel-coat

I am getting ready to do this repair. I was looking at iboats gelcoat repair kits and they have exact color match. There are billion different white colors and I'm wondering how I tell which white matches my hull. Anybody know how to tell which white will match?......Thanks


Ken

 

[Yacht Dr.]

Re: Hole in gel-coat

Its probably Arctic White ( spectrum # 1470 )

Good luck m8.

YD.

 

[oops!]

Re: Hole in gel-coat

I am getting ready to do this repair. I was looking at iboats gelcoat repair kits and they have exact color match. There are billion different white colors and I'm wondering how I tell which white matches my hull. Anybody know how to tell which white will match?......Thanks


Ken

the color is a manufacturers secret......they will tell you the name.....but not the tint.
if you call the mfgr.... they will tell you the color name.....
yd has experince in factory tints....so if he has all the info.....his call could be right

 

[Yacht Dr.]

Re: Hole in gel-coat

Just to let you know that there are a few "different" arctic whites out there .. the spectrum # 1470 is my Best guess without a hull ID # ( I would not put ID #'s on an open forum though ).

Also .. because of the age of the boat there is a slight chance that the "factory gel" will not match perfectly.

YD.

 

[1979 Quartermasters]

Re: Hole in gel-coat

Well I got the gelcoat repair kit in the mail yesterday. It comes with tinting pigmants and a chart to try and mach the color. It looks like I might be able to get it fairly close.

Thanks for the info guys, but it looks like i'm going to have to match it myself.

Wish me luck!!!

Ken

 

[1979 Quartermasters]

Re: Hole in gel-coat

Hi guys;

I'm going to start this little repair tomorrow and I have a few questions.

mix some white gellcoat with cobosil...

Is this necessary, or is the cobosil just a filler?

Secondly, do I need to cover the gelcoat for it to cure properly. I'm a little concerned that it might be hard to keep the shape on the bow while pressing the film into the repair. I don't mind sanding. I think I'm going to need to shape anyway.

Thanks.....

Ken

 

[oops!]

Re: Hole in gel-coat

forget that stupid film bud......it will only get you into trouble....i wish they would not put that stuff in the kits...

the cabosil is a filler that is used to thicken the gellcoat as a build layer.

after you grind it down and have the de lam areas back to the contact with the glass....
clean with acetone.

next.....mix your color....

this is where you are going to get frustrated......but keep at it.....

rule one.....if you go too dark....forget it....start over.

when you mix any color that is darker than your base....only use a very small drop at a time.....then mix for 5 minits
then take that new color to the repair area....and dab some on to the spot where the bare glass meets the old gellcoat.

you will see the color at that point.....adjust as needed.

this is going to take you several tries....did i say several....lol....i meant you will wear out your shoes walking back from the mix table to the boat.

use a rag with acetone to wipe your tests off the hull spot.

when you get it to where you want the color.......add your cabosil to the new color...save some color in a seperate jar.

this gellcoat should be unwaxed...please check....

use mekp at 2% of total volume of the new color.

using a paint brush.....dab the gell paste into the glass,,,,get it in the crevaces....then smear it on the whole area with the paint brush........

let allmost cure....


take a bondo spreader....and use some of the gellcoat you saved with out cabosil (catylized at 2%) and just quickly scrape the gellcoat on the area......this will fill any voids left by the brush.

wait to allmost cure.....and do it again untill the surface of the new gellcoat is higher than the surrounding old gellcoat.

walk away......let fully cure....(about an hour)

take 320 grit and start sanding any rough areas, or ridges....
watch out around the bow line....you dont want to sand thru the new gellcoat.

your paper will load (get gummed up) but just keep going....
after you have it almost flat to the contour of the boat and the ridges off....

switch to 400.....and smooth the area,.....then 600....all the way to 1500.

after 1500......take your buffer and compound polish....and polish the area.....

done.........drink beer !

cheers
oops

 

[1979 Quartermasters]

Re: Hole in gel-coat

Thanks Oops, that was very detailed and exactly what I needed!.....

Ken

 

[Yacht Dr.]

Re: Hole in gel-coat

A few more pointers if your going to do it this way .. in no particular order ..

1. When your happy with the gel mix .. transfer the WHOLE mix into a Fresh clean container and remix ( this makes sure your match does not change in the initial mixing container ).

2. Use toothpics to add the pigments ( dont try to squirt a little pigment in directly from the tube ).

3. Put 2 layers of masking tape about 1/4" around your repair area before filling. Leave the tape on until your finished with your " rough fairing/shaping ". While sanding on filler and sand through the edge of the tape line..stop sanding in that area.

4. After your done grinding out the repair.. sand/scotch bright 1" beyond the repair ( or you could get a "dirt halo" ).

5. When you think your getting close on your color matching.. dab your mix and let it sit for 3-5 min before choosing which color to add next ( the color will change after time to reveal a closer color of your cured gelcoat ).

6. Add Black last.

Hope this helps .

YD.

 

[oops!]

Re: Hole in gel-coat

2. Use toothpics to add the pigments ( dont try to squirt a little pigment in directly from the tube )

Hope this helps .

YD.

I just want to add to this statment for reference sake.

the use of tooth pics, paper clips, mechanics wire, small tie wraps or what ever fine item you can is manditory.

the droplets from a spout on a bottle are far too large.....

a VERY SMALL amount of pigment can totally change a color.

once you go too dark or too much of one color..... the batch is mostly ruined.

you need to add very very small droplets of pigment, and mix very thoroughly.

as well, the mixing takes a very long time with small amounts of pigment.

i have mixed pigment for 3 minits with a popsicle stick in a small coffee cup.....and still found large untouched globs of un mixed pigment in the batch.

you really have to mix the stuff well

 

[1979 Quartermasters]

Re: Hole in gel-coat

Thanks guys. With all that info, maybe I should look into opening a shop.lol

I went to about three places today to find find cobosil to no avail. What I did find was Silica Thickener by Systemthree and was assured this would be a suitable sustitute. You guys heard of this stuff?......

Ken

 

[oops!]

Re: Hole in gel-coat

try industrial placstics and paints.

however....fumed silica is mostly used with epoxy.....but it should be good for what you are doing.
but i dont use it.