Gelcoat Repair

[superdtf 68]

Last year the Enzo had a couple of "accidents". The first one is that we clearly hit something. I don't know exactly when it happened. It's right on the inside port chine, about 4' in from the stern. The second one happened a couple of weeks later when some nice, well-meaning folks "helped" us park as we were pulling up to the houseboat (they were visiting).

 

I totally spaced off getting it fixed, and I don't want to run it this year without fixing, and I want to make sure the hull is dry inside (especially the one on the chine). Turns out I won't be able to get it into the shop that I trust, and I've been wanting to try this repair out myself for a few years. So my intrepid over-confidence might be your gain... we'll see how it turns out.

 

Here are the damaged spots:

Chine:

 

Deck, edge of it is under the edge of the vent cover:

 

 

This post has been promoted to an article

[superdtf 68]

Here, I've cut, gouged, sanded, and just generally cleaned up any loose fiberglass and splintered gelcoat. I use a very sharp shop knife for splintered gelcoat and to cut any crazy fiberglass that may be sticking up. Then I use course sandpaper, like 80 grit, to sand out the damaged area. I take EXTREME care to not get out of bounds with that stuff, otherwise I could end up expanding my repair area 10x.

 

Sanded, ready for filler:

 

 

Sanded, ready for filler:

 

 

Looks wet, because I just cleaned it with solvent prior to applying filler:

 

Edited June 8, 2012 by superdtf

[superdtf 68]

Now, I'm ready to put the filler in. Because one of my repair areas is right on the chine, I've chosen a 3M High Strength Marine Filler. It's awesome because it's crazy strong and hard. It sucks because it's crazy strong and hard... and I have to sand it. So I use a Stanley Surform tool when the filler is going off, right before it turns rock hard, to get it in the right shape. Then I quickly switch to 80 grit (taking great care to stay in the repair area) to take it down to rough shape before it turns to stone. If your repair is not in a critical area, then you would use 3M Marine Filler. I could have used that for the deck repair, but I didn't want to buy two different fillers, and I knew I'd use some Finishing Glaze anyway - more on that later.

 

Filler pre-shaping, on the chine.

 

 

Rough sanded

 

 

Second application of filler, rough sanded.

 

 

Deck repair, rough sanded

 

Edited June 8, 2012 by superdtf

[superdtf 68]

So, the 3M High Strength Marine Filler will have voids and pinholes, whereas the 3M Marine Filler is less likely to have them. So I knew I needed to use a finishing glaze. The best one I've ever used happens to be recommended for marine use, it's the 3M Flowable Finishing Glaze. This stuff is kinda like the red or green spot putty you'd use on your car paint job, but more work to use it, with expectedly better results. It's two part and needs creme hardener. Also you can thin it with Acetone or Lacquer thinner to get it to the consistency you want. It's opacity is high, so regardless of what color your hardener is, the glaze turns out off-white.

 

Here, I thinned it down to bondo consistency (maybe a little runnier) and applied it to my repair areas. This stuff flows. It will fill the little cracks and pinholes, the sanding scratches I made in the original gelcoat, etc. When it goes off, it goes off FAST. But it's super sandable, so no worries. I used 320 grit to sand it, and feathered the sanding around the repair area (gelcoat will fill scratches from 180 grit on up).

 

Ready for finishing glaze:

 

 

 

First pass at glaze and sanded:

 

 

 

Second application of glaze, and sanded. Taped off, and ready to spray.

 

 

 

Chine repair, glazed, sanded, taped off and ready to spray:

 

Edited June 8, 2012 by superdtf

[superdtf 68]

It might be a day or two before I finish this. I plan to spray tomorrow.

[truekaotik 458]

What are you spraying? Also may I ask why you didn't call spectrum and get the exact gel color in a patch kit and do it once instead of 3 times? That is the manufacturer of the gel coat for all boats.. I am just curious

Looks great so far though

Edited June 8, 2012 by truekaotik

[superdtf 68]

What are you spraying? Also may I ask why you didn't call spectrum and get the exact gel color in a patch kit and do it once instead of 3 times? That is the manufacturer of the gel coat for all boats.. I am just curious

Looks great so far though

I spoke with Gloria (Shel's new right hand) at Fineline and ordered the exact gelcoat from Spectrum. I tested some un-catalyzed gelcoat for color match, and it's perfect. As for doing something three times instead of once, I'm not sure what you mean.

[truekaotik 458]

I was referring to the 3m patch first then the gel... 2 times I guess, my fault... At first I read it as you used two different 3m products and then spraying something... My bad...

Anyways I had some minor damage, not as extreme as yours but in SEVERAL places and used the quart gel patch kit from spectrum and it looks perfect after one fill and wet sanding and polishing... That's why I was curious why you used the 3M product as well? thanks, I'm always looking for explanations when I don't understand

[superdtf 68]

I was referring to the 3m patch first then the gel... 2 times I guess, my fault... At first I read it as you used two different 3m products and then spraying something... My bad...

Anyways I had some minor damage, not as extreme as yours but in SEVERAL places and used the quart gel patch kit from spectrum and it looks perfect after one fill and wet sanding and polishing... That's why I was curious why you used the 3M product as well? thanks, I'm always looking for explanations when I don't understand

That makes sense, the gelcoat with patch aid can fill shallow damage to the gelcoat (as in the damage doesn't get beneath it). In both places, mine was into the fiberglass; especially with the chine damage, I wanted to make sure the repair would withstand the pressure of constant redirection of water force at high speed. So, the place I'm at now in the process, is about where you started (If I understand correctly).

[superdtf 68]

That makes sense, the gelcoat with patch aid can fill shallow damage to the gelcoat (as in the damage doesn't get beneath it). In both places, mine was into the fiberglass; especially with the chine damage, I wanted to make sure the repair would withstand the pressure of constant redirection of water force at high speed. So, the place I'm at now in the process, is about where you started (If I understand correctly).

 

That makes sense, the gelcoat with patch aid can fill shallow damage to the gelcoat (as in the damage doesn't get beneath it). In both places, mine was into the fiberglass; especially with the chine damage, I wanted to make sure the repair would withstand the pressure of constant redirection of water force at high speed. So, the place I'm at now in the process, is about where you started (If I understand correctly).

 

So, to be clear, I used High Strength Filler, then FInishing Glaze, and now I'm ready to spray the gelcoat.

[truekaotik 458]

I got you. Your damage was severe enough for extra piece of mind you went with a very hard inside patch Mine wasn't a finish coat, but a paste with catalyst. So even on the damage that went almost to the fiberglass it filled them nicely with a small bump after drying... You got the thinner sprayable gel coat for your finish aposed to the actual paste patch kit I get it now... Thanks man now I know if it penetrates the fiberglass I need to reinforce the damage first prior to patch.... I have done this several times and this is the first I've had someone do it your way.. Nice to know bro

[superdtf 68]

I got you. Your damage was severe enough for extra piece of mind you went with a very hard inside patch Mine wasn't a finish coat, but a paste with catalyst. So even on the damage that went almost to the fiberglass it filled them nicely with a small bump after drying... You got the thinner sprayable gel coat for your finish aposed to the actual paste patch kit I get it now... Thanks man now I know if it penetrates the fiberglass I need to reinforce the damage first prior to patch.... I have done this several times and this is the first I've had someone do it your way.. Nice to know bro

I think the way you did yours is easier. Easily I could have done the deck repair like that; and possibly the chine, but I wanted to be confident on that one.

[superdtf 68]

OK, so I sprayed the gelcoat this evening. I was a bit anxious mixing up the gelcoat, thinned it a bit, added patch aid, and then added the hardener. I ended up without about 1.5 cups of gelcoat mixture. It was SUPER EASY to spray. I started by laying down a solid layer over the repair area, then feathered outward going lighter towards the tape (so that I don't have a ton of material to take down when I go to blend it. I was also anxious about the working time (they say 15-30 minutes), but I was done spraying in like 3.

 

Deck repair sprayed. The lighting made it hard to see, but I'm very pleased.

 

 

 

I could tell that this one won't turn out quite perfect. I laid a lot of gelcoat on this one so that I can do a little work on shaping/blending. If it doesn't turn out, I can re-spray it. (oh yeah, it's underneath the boat, however it turns out will be great)

 

[WakeDoc 471]

Fantastic write up, for sure will help other Crew members in the future!

[truekaotik 458]

Nice Man!! Can't wait for shiny pics next

[superdtf 68]

Additional notes:

• Everything I read indicated that I should thin it for spraying with Styrene (resin thinner). I could not find any in the great state of Utah. I found that several old-timers used lacquer thinner; said it was good to 10% and interfered with the resin/catalyst less. I thinned it very little, probably 6-8%.
  
• So I started to get worried that the gelcoat wouldn't "go off". But sure enough, about 55 minutes after mixing, I checked the container that I had poured the remaining gelcoat in when I washed out the spray gun, and it was hotter than hell and solid!
  
• The spray gun I used was a cheap Campbell Hausfeld with the standard tip (2.5 I think); it's a knockoff of a Binks Model 7. I think I paid like $50 bucks for it years ago. It's been more than adequate for the occasional lacquer job that I do on furniture and odds and ends for my wife.
  
• The hose air pressure that turned out nice for how much I thinned the gelcoat (as in not very much) turned out to be 60 lb's, which is on the very low range of pressure from the sources I read.
  
• I used lacquer thinner to clean out the gun. Worked great.
  
• After an hour and a half, I was able to remove the tape with zero problem. I'm pleased with the colormatch. It's recommended to wait 24 hours before sanding. That's alright, it's late now, and I have a family reunion lunch tomorrow.
  

Edited June 9, 2012 by superdtf

[islander033 2]

Great write up!

[superdtf 68]

OK, so I removed the tape and paper, and this is what it looked like:

 

Ready to sand:

 

 

Ready to sand:

 

• Notice how "orange peeled" it is. This is expected. I CAREFULLY wetsanded with 320 grit and a sanding block to smooth out the orange peel. Then I used some 320 wet with my fingertips to feather the edges.
  
• From there I switched to 600 grit wet sandpaper. I wetsanded with the block on the chine, and used my fingertips on the deck repair.
  
• Then I moved to 1000 grit wet sandpaper. I took care to avoid pressure points and cover everywhere I'd previously sanded.
  
• At that point, I pulled out the air hoses and fired up the ingersoll-rand buffer. I used 3M FinesseIt II - I've always felt like it was about 1600 grit. It really took no time at all to buff it.
  

From start sanding to finish buffing was maybe an hour and a half, with plenty of interruptions (remember, five kids). Here's what it looks like:

Chine repair sanded and buffed:

 

 

Deck repair sanded and buffed:

 

 

Deck repair sanded, buffed, waxed, and put back together:

 

 

If I look very closely at the deck repair, I have a couple of very faint scuffs just above the rub rail that I missed with the 1000 grit. My wife couldn't see them (not surprising). I'll touch that up next time I have the buffer out. As for the chine, I have a couple of 3-4mm "dimples" right on the corner of the chine. Nobody will notice but me, and I've halfway talked myself out of fixing them, so please don't say anything about that (besides, you can't see it ).

 

Overall I'm very pleased. My wife was actually wowed. Ten years ago my humor and my feats of DIY would get a reaction from her, but I tell her it's like heroin, you get it regularly and you stop noticing it, it doesn't get you high, it just feels "normal" until you have to do without.

[hurricane sean 6]

Great job it looks awesome. It makes me feel like I could tackle something similar. Thanks for the great write up.

[Sporty 4]

Wicked awesome write up. Extremely helpful. This is my next project! now I have the confidence to tackle it!

You rock. Thanks.