Fixing my damaged keel

[ScotWithOne_t]

Re: Fixing my damaged keel

I went ahead and purchased the stuff woodonglass posted. $38 for a pint! $58 for a quart of white gelcoat! It's like half that online. Ugh... I guess that's the price to pay for the luxury of not having to wait a week and a half to receive goods.

I did some more grinding today, and took away more of the white fiber. There is also some darkish yellow fiber in kind of a second tier perimeter of the bad part. I didn't sand that away because it seems to be deeper beneath the still-good glass. .

I used a 2.5" hole saw and made a 4" square hole in my ski-locker to inspect from above. It seem the boat has about 1/4" of resin on top of the actual fiber. I know this because in the very middle, it was cracked and chipping away. Put a nice cut on my finger from it (which I was reminded of later when I got some acetone on it ) I'm afraid I'm going to have to resort to mushing filler into the cracked resin on the inside, since it is not accessible to grind. The only way to get at it would be to rip out the entire interior and floorboards. I'm not doing that. At least not yet. I'll take my chances with laminating from the bottom, and using filler on the top-side in hopes to keep water out of the cracked resin. If it fails, then I guess I'll have to do it the long, hard, "right" way by removing the interior, and I'll be right back to where I am now, so I at least have to try is the easy way. So I appreciate your advice and concerns, and I don't want anyone to think I'm ignoring the advice because I'm definitely taking it under heavy advisement, but like I said, I don't have a lot to loose by doing it this way first. Hopefully what I'm doing will last for several years though, considering the boat will probably get used 5-10 times a year, and is trailered.

I did a test run with the resin and matting tonight be laying two small strips on the worst part. This area will need to be built up a bit anyway since I ground away more of it tonight. In total, it will have 5 layers on that spot. This is some messy stuff.

 

[Woodonglass]

Re: Fixing my damaged keel

Yeah Worst Marien, I mean West Marine is HIGH DOLLAR but your right about getting it when you want it. Can you get your hand down into the hull and do any sanding on the inside? If you can then PLEASE try and sand someof that old glass on the inside and try to lay two or three lams of glass in there. If you do that you just MIGHT get this repair to last a LONG time. I KNOW you KNOW the right way and you are taking the EASY way but IF you could get some sanding and some back up lams in there it would be a GOOD thing.

I'm just sayin...

 

[ScotWithOne_t]

Re: Fixing my damaged keel

Yeah Worst Marien, I mean West Marine is HIGH DOLLAR but your right about getting it when you want it. Can you get your hand down into the hull and do any sanding on the inside? If you can then PLEASE try and sand someof that old glass on the inside and try to lay two or three lams of glass in there. If you do that you just MIGHT get this repair to last a LONG time. I KNOW you KNOW the right way and you are taking the EASY way but IF you could get some sanding and some back up lams in there it would be a GOOD thing.

I'm just sayin...

I'll do what I can for the top side. Trouble is, the aft-most part of the ski-locker is at the front-most part of the light-in-color part of the damage. If I drill a few more holes in the ski-locker, maybe I can fit my whole arm in there and kind of blindly-sand it, and stuff some matting in there.

I'm not sure why there is a 1/4" of pure resin on top of the roving on the top side. I'm guessing that when they built the boat, they laid down all of the matting, roving, etc, and then slathered on an extra layer of resin, but a lot of it settled into the keel. As it is now, It's all chunky and busted apart (obviously flexed a little during impact and broke a lot of it since resin is brittle). That's why I thought I'd try to rig up some sort of plow-shaped device on the end of a stick and mush some filler into the broken resin. I know it wouldn't do much structurally, but it would at least help keep water from getting at the glass from the top, no?

Anyways, my progress so far is that I've sanded the cured resin from the two small patches I put up last night, and laid two more smallish pieces to fill in the significant depression I made from the extra grinding I did to the "white" area.

I just hand-sanded last night's patches with 60-grit, and this is what it looks like.

Notice the speckled white spots. I'm not quite sure what that's from. Was my matting too lean? Not enough resin? I put quite a bit on. Or could it be air-bubbles? The spots are pretty much on the surface, not embedded within (at least that I can see).

I stippled a bunch of resin into those spots for good measure before I put up two more patches, and also two long, skinny patches along the starboard side scrape.

(don't worry.. that super white spot is overexposure form the flash)

Couple of questions for veteran fiberglassers:
1) the resin was still a wee bit tacky this morning. It was applied last night at 8pm, so it's had WAY more than the 2-hour cure time to harden. I thought this type of resin was waxed, and therefore not supposed to be tacky when cured.

2) when laying the 4 small patches at once today, by the time I got to the 4th patch, the resin was getting very gel-like, and harder to work with. Is there a way to increase the time it takes to cure? The can says 14 drops of catalyst for each ounce of resin. If I use, say, 10 drops per ounce, will that slow it down, or just screw it up and it well never fully cure?

Thanks,
-Scot

 

[ScotWithOne_t]

Re: Fixing my damaged keel

I'm going to do the larger patches today. I want the resin to have a longer working time. The weather today is about the same as yesterday (~85?F) and yesterday, 14 drops/oz was setting/kicking a little too fast. If I had been doing the larger patches I would have been screwed.

I did some reading, and it seems that for poly resin, 1- 1.5% catalyst is supposed to be used.

The can says to used 14 drops per ounce.

A little math:

1 drop = 1/20th of a mililiter = .05 mL
1 oz. = ~30 mL

14 * .05 = 0.7 mL

0.7mL/30mL = 0.023 = 2.3%

Seems higher than what some people are using. I'm going to knock that down to 1.5%, so...

1.5% = 0.015

30mL * 0.015 = .45mL

0.45mL / 0.05mL/drop = 9 drops per ounce of resin.

I'll probably use 4 ounces of resin, so 36 drops of catalyst.

Anyone see a problem with this? Should I reduce the catalyst even more so that I get a longer working time?

If I use TOO little cat. can I cure it by adding heat with a heat-gun?

Thanks,
-Scot

 

[Woodonglass]

Re: Fixing my damaged keel

I would recommend mixing smaller batches and staying with the recommended ratio if you want to ensure that the resin hardens correctly. You can reduce the cat to give you more time but IMHO it WILL affect the strength of the end product. The best way to give your self more time is to start early in the morning with cooler temps. Starting with temps in the 70's will give you a LOT more working time.

I'm just sayin...

 

[ScotWithOne_t]

Re: Fixing my damaged keel

I would recommend mixing smaller batches and staying with the recommended ratio if you want to ensure that the resin hardens correctly. You can reduce the cat to give you more time but IMHO it WILL affect the strength of the end product. The best way to give your self more time is to start early in the morning with cooler temps. Starting with temps in the 70's will give you a LOT more working time.

I'm just sayin...

Not sure what you mean by using smaller batches.

Say I want to do 3 lams that are increasing in size, and the small batch of resin gets too thick to use after I'm just sticking on the 2nd lam. Don't I have to wait several hours, sand, then do the 3rd lam? Or is it okay to mix another batch, and apply another lam over semi-cured resin?

 

[ScotWithOne_t]

Re: Fixing my damaged keel

Just did two more small patches. That's 6 lams now, and I haven't even gotten to the big pieces I cut out in post #12. I'm more or less just building up thickness right now, since I ground away so much off the keel.

I put a straight edge across the keel and there was about a 3/16" gap that I need to fill (that as before the recent 2 lams).

I timed the resin this time, and it took about 7 minutes to get to a jelly consistency and was hard to work with. Luckily with these small patches, I'm done wetting laying by about 3 minutes. The bigger pieces might give me trouble with that short of work time. Oh well.. I have a couple hours to kill now while this lam hardens. Then it's sanding time again. Joy.

 

[JAFO1]

Re: Fixing my damaged keel

What size batches are you making? I'm not familiar with the drops method of measuring.

 

[ScotWithOne_t]

Re: Fixing my damaged keel

What size batches are you making? I'm not familiar with the drops method of measuring.

I've just been making 1oz batches. That's all I really need for the size pieces I'm putting on right now. When I do the bigger pieces, I'll probably use 3 or 4 ounces.

 

[ScotWithOne_t]

Re: Fixing my damaged keel

Finally finished the fiberglass laminating tonight. Final (10th) layer was fiberglass cloth instead of mat. Just have to clean up and feather the edges with the grinder tomorrow and then I'll be done with grinding too!!

Here's the latest and greatest progress pic:

My roller had seen better days. The piece I put up tonight was bigger than the others, so the resin got pretty gelled by the end, and I don't think I got the roller into the acetone bath soon enough. Oh well, this is the last time I'll EVER need to use one. *crosses fingers*

Note the resin between the washers. It might still roll though, just not as nicely. And IF I ever have to do this again I'll just make a new one for a few bucks. Sure beats the $20 they want for them at the store. (if you haven't figured it out by now, I'm rather frugal.)

I also decided to give gelcoating a test-run. There was a small area that got scratched that I used to test my application method. I was thinking of roll & tipping, but a foam brush worked just as well (maybe better).

I was a little concerned that the gelcoat was still "wet" after about 20-30 minutes, so I started in with the heat gun. I guess I should have waited, since I found this a while later.

I think I was just paranoid that I mixed too little catalyst, since I'm used to the poly resin setting up in like 8 minutes tops.

 

[Woodonglass]

Re: Fixing my damaged keel

Well swot, looks like you are almost there. What did you use to thicken your Gel coat?

 

[ScotWithOne_t]

Re: Fixing my damaged keel

Well swot, looks like you are almost there. What did you use to thicken your Gel coat?

Nothing. That's kinda what the trial run was for. I wanted to see how it flowed by itself before I went out and bought more stuff. It's pretty viscous on its own, so I'm not sure I need to thicken it. I globbed it on pretty heavy, and it's definitely thicker than the original, so I'll be able to sand it flat and smooth.

IIRC from the Paint vs. gelcoat thread, the purpose of adding a thickening agent (either glass bubbles or body filler) was to make the gelcoat viscous enough to build up thickness in one coat. If I can build up the thickness I need without said thickening agents, is there really any reason to do so? I haven't seen that technique used in any of the gelcoat tutorials I have read.

 

[Woodonglass]

Re: Fixing my damaged keel

Hey, if you can get it on as it sits then go for it. It usually runs all over the place on me but if it's workin don't mess with it.

I'm just sayin...

 

[JAFO1]

Re: Fixing my damaged keel

Don't trash that roller. You can pick the resin off. Looks like you could pop the clips off and clean it up.

 

[Friscoboater]

Re: Fixing my damaged keel

I just read this entire post. It looks like you are on the right track. I agree that there needs to be some repair on the inside too for strength.

 

[ScotWithOne_t]

Re: Fixing my damaged keel

Don't trash that roller. You can pick the resin off. Looks like you could pop the clips off and clean it up.

Probably so. If not, I'm only out a couple bucks worth of flat and fender-washers.

 

[ScotWithOne_t]

Re: Fixing my damaged keel

Daily progress report:

Finally done sanding fiberglass! Oh happy day! (although I think gelcoat dust is just about as bad)

Did some mudslinging today:

block-sanding will be tomorrow night's task... if it's not raining. Possibly gelcoat as well.

Side note:
the gelcoat I applied last night has dried and hardened, but if I push hard, I can make a mark in it with my fingernail. Will it continue to harden over time? This is supposed to be the "finish" type of gelcoat, so it doesn't remain tacky, but doesn't seem to have cured 100%. Does the cure take longer than a day normally?

Assuming I get done gelcoating tomorrow night, will it be water-ready by Saturday or Sunday?

 

[Woodonglass]

Re: Fixing my damaged keel

Are you sure it has wax!!! If not it will NOT fully harden.

I'm just sayin...

 

[ScotWithOne_t]

Re: Fixing my damaged keel

Are you sure it has wax!!! If not it will NOT fully harden.

I'm just sayin...

Hmm... I guess I can't say with 100% certainty that it has wax, but it is the "finish" coat stuff.

I wonder if it was too cool outside last night. Overnight low was 68?F. I may have been a couple drops short on the catalyst... would that do it?

 

[Woodonglass]

Re: Fixing my damaged keel

Yep, sure would. Would take it longer to flash off. Give it some time and see if it will eventually get hard. If not you will have to re-do it.

I'm just sayin...