marine tex vs. gelcoat for screw holes.....

[CliffA]

i have maybe a dozen or so screw holes in my gel coat left over from removing unused electronics and replacing my swim platform ladder....currently i have them plugged with outdoor silicone but i want to make a more permanent repair....i have a jar of matching gelcoat paste from spectrum and i also have some white marine tex epoxy.....i want to fill the holes in for asthetics reasons only....i will not be putting screws back into the holes....i have used the marine tex before and like its strength and easy use but it is a bright white color where my gelcoat is off-white....i have not used the gelcoat repair paste from Spectrum yet so i have no experience with it...i have read that there is a good chance it will not match the gelcoat either due to to the sun fading the original gelcoat on the hull....

any opinions on which i should use to fill in the screw holes?....can the marine tex be sanded smooth and buffed to a shine once it sets?......if i use the spectrum paste is it as simple as backing the hole with some tape on the backside and dabbing some of the paste in the hole then sanding and compounding out once it cures?

thanks...
cliff

 

[Bucit]

For strength you could tape off the back of the hole, fill 3/4 of the way with marine tex and then finish off with the gel coat in hopes it matches. This way if you or the next owner wants to put screws in the holes they will hold. Marine tex can be sanded but not sure how shiny it gets after buffing.

 

[MonacoMike]

if your gelcoat is older than a year, it is unlikely you have any usable gelcoat. Mine went bad in a little more than a year. Shelf life sucks, it got all lumpy

MM

 

[Woody]

For strength you could tape off the back of the hole, fill 3/4 of the way with marine tex and then finish off with the gel coat in hopes it matches. This way if you or the next owner wants to put screws in the holes they will hold. Marine tex can be sanded but not sure how shiny it gets after buffing.

:thumbsup:

 

[Lazy Daze]

You can get it (M.T.) pretty shiny - but I've never really "gone to town" on it to see how shiny I could really get it. My guess is not as shiny as gelcoat. I think you have a better chance of the gelcoat coming closer to matching.

 

[CliffA]

thanks for the replies...the spectrum gelcoat paste is older than a year but it has never been opened....i don't know if that affects the shelf life or not....guess i will just have to look and see.....most of the screw holes are in spots where the gelcoat is not very thick so trying to partially fill the hole with both MT and gelcoat would be difficult.....i may try both products in different holes to determine which i like best...is there anything special to do when using the gelcoat?....is it as simple as filling the hole and then sanding/buffing when it cures?

cliff

 

[stupe]

For what its worth... I used MT to repair a chip I had on my swim platform. Although it was easy to make the repair, the color didn't match and over time (3+ years) the sun killed the MT. It started to crack a little but worse was the color changed. It's now an obvious repair. Although, any small repairs I made with MT to the bottom of the boat look perfect still.

 

[CliffA]

For what its worth... I used MT to repair a chip I had on my swim platform. Although it was easy to make the repair, the color didn't match and over time (3+ years) the sun killed the MT. It started to crack a little but worse was the color changed. It's now an obvious repair. Although, any small repairs I made with MT to the bottom of the boat look perfect still.

good to know, thanks....all of the holes i need to repair will be in the sun so maybe MT is not the best product to use....

cliff

 

[MonacoMike]

Cliff, the correct gelcoat for your boat will not be a perfect match as you likely have sun fade or yellowing to some degree. In fact different areas may need different tints to blend invisible. I used a tinting kit to get color right before finalizing the repair. I wanted to keep some gelcoat on hand but my guys said it would just go bad. In my area the few folks that do gelcoat repairs often check recent inventory with each other before ordering in gelcoat for small repairs to cut costs.

The first time I got a bid to fix a few small holes it was off the chart high, I asked why and it was the supplies if which I needed only 10% of and the extra that came with it. I kept the previously opened gelcoat tightly sealed in the house and it still separated and seized.

Good luck, MM

 

[Lazy Daze]

You'll want to enlarge the hole first and get rid of the jagged edges. A drill bit twice as large as the hole and spun gently by hand will do the trick. In the end, you're looking for the hole to have a shallow "V" appearance (chamfered). Blow/sweep/vacuum/whatever the hole out and then clean with acetone. Over fill the hole slightly.

 

[CliffA]

thanks for the replies and ideas.....i am not 'so anal' that the color match has to be perfect, but i do like to do things the best i can...after all this is a 15 year old boat.....luckily these are relatively small holes and not a larger repair that a color mismatch would be more evident.....i have some counter sink drill bits that should give a nice taper to the hole and clean them up good before i apply the gelcoat...i might run them in reverse in the drill to be sure not to take chuncks out of the gelcoat around the edge of the hole....i will assume that the jar of gelocat paste is a one use portion and will likely have to dispose of the portion not used...has anyone tried putting the unused portion of the gelcoat in the fridge to see if it keeps longer the way that 3M 4200 and 5200 does?....seems such a waste to just throw it out....

cliff

 

[MonacoMike]

My gelcoat from Spectrum was in a quart paint can and the hardener in a tube. West Marine gelcoat is in a paint can too. Do you have a small tube of each? The first time I applied I ended up removing it and doing over. Hope you have enough to get a second shot.

MM

 

[Lazy Daze]

The only downside to a countersink bit is that they typically have a steeper angle - you mentioned you're going into a thin area? You may end up making the hole much bigger than wider.... I'm not sure I explained that correctly...

 

[CliffA]

The only downside to a countersink bit is that they typically have a steeper angle - you mentioned you're going into a thin area? You may end up making the hole much bigger than wider.... I'm not sure I explained that correctly...

you explianed it well....i understand what you mean....the larger drill bit would work better to taper the hole edges in areas where the gelcoat is thin....

thanks....cliff...

 

[CliffA]

My gelcoat from Spectrum was in a quart paint can and the hardener in a tube. West Marine gelcoat is in a paint can too. Do you have a small tube of each? The first time I applied I ended up removing it and doing over. Hope you have enough to get a second shot.

MM

Mike, it has been so long since i got the spectrum gelocat i can't remember what all was included.....i do remember just getting a small container of the gelocat (much smaller than a quart) because i did not have any significant repairs to make, only filling in some screw holes....most likley there was a small tube of hardener included as well as some basic instructions....i'll have to find the box and take a look.....i should have enough gelcoat and hardener to take a second shot at it if needed.....

cliff