Sea Ox Rebuild

Questions about boat repairs with our resins and fiberglass: hull patches, transoms and stringers, foam, rot etc.
Dipper
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Re: Sea Ox Rebuild

Post by Dipper »

Thanks for the clarification fallguy. You addressed my exact concern with the cracking. That was basically what I had imagined the correct procedure should be. Thanks for spelling it out for me as far as the process.

I have definitely noticed how difficult it is to keep the 1700 square and in shape. The only 1708 I have at the moment is 4 and 6 inch tapes so I will have to order some unless I can find it local.

And just to confirm it will be a 1.5inch coosa core and I will be adding knees in the end very similar to Pamlico's build.

I had planned to sand down the gel coat and taper grind to allow for 1 or 2 layers to the outside (just wider than the tunnel) since I will be wrapping the tunnel glass from the bottom of the boat onto the back of the boat anyway. Im am sure I am in for a crash course in fairing before this is over. The boat will be painted when all said and done.

Dipper
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Re: Sea Ox Rebuild

Post by Dipper »

Question for you guys because I want to make sure Im getting a good bond when I have to let a section cure before proceeding.

So I know I have to sand in between layers if the epoxy has cured. First how do I know when it has cured to a point that its safe to sand? It is taking about 36 hrs to get to the point where I cant press a thumbnail into it but even then the glass doesnt quite feel as stiff as it does after say a week.

Second, what is the correct proceedure for surface prep between coats. I can rough the surface and knock down any fibers sticking up but I cant sand the low spots in between the weave without sanding into the glass.

Should I be letting the last layer cure for a short time and then filling the weave with epoxy while its still green? If so and I have a section that I did not do that on, what should I do to prep it before proceeding with additional layers?

fallguy1000
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Re: Sea Ox Rebuild

Post by fallguy1000 »

Corning is the key, or gumming on the paper. If you can sand without corning (epoxy balls) or paper gumming; let that be the guide.

Epoxy doesn't cure below about 60F worth a hill of beans. Just the facts. Best to add a lightbulb or small electric heater to the space.

I always sand all shine after about a day. 40-60 grit paper or so is ideal key. A nickel or dime is sort of the standard; nothing bigger is allowed. Some low spot shine on stitched fabrics is normal; don't drive yourself crazy sanding it away.
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Dipper
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Re: Sea Ox Rebuild

Post by Dipper »

So I got the cutout filled in and added 3 layers to the inside of the outer transom skin. Will start sanding in prep to glue in the core tomorrow. I also have to figure out my clamping program to make sure theres good contact. I have a 2x10 that I plan on running some bolts thru but ill have to get it all dry fit and see how it looks.

When I dry fit the glass for the cutout it was pretty much perfectly fair but after wetting it out and letting it cure there is a very small section that is higher than the rest where layers overlapped. I am afraid to sand it too much because i dont want to compromise the strength. Should I use some fairing compound to try to fair it out a bit before gluing in the core? We'll see how close the fit is tomorrow but how perfect should I worry about getting it? In other words will the epoxy fill an 1/8" void +/-?
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fallguy1000
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Re: Sea Ox Rebuild

Post by fallguy1000 »

Prefair it.
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viewtopic.php?f=12&t=62495

Dipper
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Re: Sea Ox Rebuild

Post by Dipper »

Sorry for the no posts guys. Its been nose to grindstone around here. I have gotten quite a bit done on the boat and work has been crazy at the same time.
Ill try to get caught up. I got the outside skin faired and glued the coosa transom core in.
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It made good contact so glued it in, let it cure and and after a sound test with a hammer it sounds solid throughout.

Dipper
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Re: Sea Ox Rebuild

Post by Dipper »

Next I filled any voids around the coosa with thickened epoxy and went ahead and made my fillets to be ready for glass.

Sanded it all and cleaned everything up real good. Ended up laying 5 layers on the inside of the coosa and overlapped out onto the bottom, tunnel, and hull sides 12,10,8,6,4. With a couple darts cut it all layed out fairly well.

On the top I made the coosa about an inch and a half shorter than the outer skin, routed the inside edge of the coosa to 3/8" and layed a fillet between the coosa and the outer skin. The inner skin then went up over the coosa and bonded with the outer skin. This encapsulated the coosa and seemed to really add strength.

It all went fairly well considering that this was my first transom rebuild. It cured very solid and seems strong. I will still be adding knees to help distribute the load from the motor since it will be on a jackplate.
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Dipper
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Re: Sea Ox Rebuild

Post by Dipper »

So far the project seems to be going well. One of the biggest struggles so far has been the fact that it gets up to 85 or 90 degrees in the shop during the day and yet 35 and down to as low as 20 at night.

I have been running heaters to try to maintain a more steady temp in the evening but it has taken quite a while for full cure since I am using slow hardener. The extended working time has been nice but it has been challenging at times to get the glass to wet out properly since the resin is thicker than Id like. I have run a heater to keep the resin above 60 degrees also but as the temp drops in the shop it becomes a loosing battle.

That being said I am satisfied with the results so far.

I started cutting out the remaining floor, stingers, and foam and had a little more flex in the hull than I was comfortable with so I braced things up more and got it where it wouldnt move.

Today I finished cutting floor and stringers which is where I am at the moment. There is a lip left from the floor that I will be removing also and then on to grinding/sanding to prep for the new stringers.

I burned up my oscillating tool today and have been looking at new ones. Been considering the fein multimaster. Any preferences out there?
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fallguy1000
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Re: Sea Ox Rebuild

Post by fallguy1000 »

Fein os the gold standard..
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pee wee
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Re: Sea Ox Rebuild

Post by pee wee »

I have an early model Fein that's continuing to do well, but I also picked up a Rockwell on sale and I have to admit that it works just as good. Don't know if it'll have the longevity, but there was a huge price difference (4 or 5 x).
Hank

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