Sea Ox Rebuild

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

Post by Fuzz »

Are you planning on flipping the hull at some point? I ask because while you can do overhead glass work it SUCKS! I would really hate to need to do much grinding and fairing over my head.

fallguy1000
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Re: Sea Ox Rebuild

Post by fallguy1000 »

Darnit. Loat another post!!

The entire transom/hull edge must be square for planing hulls for clean exit or the boat will perform I'm told 1-3% poorer.

I did mine with boards and ship tape clamped to the transom. I used a 50/50 mix of cabosil and milled fiber and epoxy a bit over 2:1 by volume, bit cabosil is probably just as good. To get a nice tight fit to the hull, I had to clamp and shim both. Epoxy won't stick to ship tape, but it will a board. It took about two fairings after the board to get it looking good and a couple more for perfection. I decided the transom top looked beefier finished square as well. Paint doesn't stick on sharp edges, so a light breaking of the edge is needed.
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fallguy1000
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Re: Sea Ox Rebuild

Post by fallguy1000 »

I also assumed a flip or even setting on side.

The hull needs a taper grind for the exterior glass that will go across the entire tunnel. You'll need a tyvek suit and faceshield and goggles and basically some way to close your head/neck to try it upside down. And you'll need to make some sort of glass holding mould that will be the opposite of the tunnel. A lot of times the mould that was used for the tunnel can be used for the glassing jig.

Glassing upside down often results in a big pile of fiberglass in a wad on the floor after you failed to get it to work carrying it and holding it. In your case, the glass really needs to be precut and prefit well which is also hard to do well enough working upside down.

If you attempt it upside down, roll the wetted glass up from the transom to the forward edge, then start at the forward end. Doing it the other way will be damn hard. Have a second person that can hold the starting glass. It is basically as slick as grease at the beginning. You can try a holding jig as well, but I think unrolling can work here. For complex shapes, a jig is vital.
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Dipper
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Re: Sea Ox Rebuild

Post by Dipper »

I think I will have to flip (not sure yet how but we'll cross that bridge when we get there). Cant really imaging fairing upside down. Reminds me of trying to mud ceiling sheetrock. Seems like it will never get right.

I can see how the edge will need to be square for the flow of water to to perform correctly back to the prop.

Im going to get some stuff ordered today but having a hard time getting comfortable with my calculations for amount of glass. Figured maybe I should just order a whole roll. On the fence about going with 17oz 45/45 like Pamlico or 1708. I realize 1708 will get you your desired thickness more quickly but if the mat is of little strength it seems like in the end the 45/45 would be stronger. I decided to do everything out of 3/4" coosa bluewater 26 after speaking with their tech guy and I believe I will order 10 gal of epoxy at a time.

We've got a week of high 90s out of the blue here so my workshop is like a sauna but I'm going to try to get some more demo and grinding/sanding done in the morning early. Will try to get an updated pic or two uploaded. Thanks again guys, this would be a lot harder without you all.

Fuzz
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Re: Sea Ox Rebuild

Post by Fuzz »

The mat in 1708 helps to build thickness and is needed when working with poly. It is also the cheapest pound for pound. If you are going to use epoxy I would go with 1700. Epoxy does not need the mat and it will not wet out the mat very easily. You will need more layers of 1700 to build thickness but you will end up with a better product. Some folks who use 1708 wet it out in a tray, roll it up, and carry to the work. I find this to be a real pain in the butt. 1700 wets out easy enough I do it in place.
When it is time to flip the hull it is not too bad. Build a cradle with one side rounded and it will roll right over. Years ago I flipped a 36x12 and a 32x13 hull and it was not as hard as I thought it would be.

fallguy1000
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Re: Sea Ox Rebuild

Post by fallguy1000 »

You plan to save the exterior transom skin?

Good choices. 1708 builds a bit faster than 1700 db. You don't need it with epoxy at all. And 1700 is okay. 1700 is a lot snakier is all. It works poorly where you need stability. Laying in layers over the tunnel would be nicer with the 1708, but no problem to do with 1700.

Added post submit.


1708 is also nocer for dry fit and removal for later because less likely to deform. When I use 1700, I am more careful to mark out references on it, even lengthwise references on hull and glass to get the length closer on rollout. You'll want to protect it more with 3" tubes as well. Rolling it is best for any larger pieces. I avoid taping it to the rolls.
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Dipper
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Re: Sea Ox Rebuild

Post by Dipper »

Just got off the phone with Jeff and will be speaking with Reid in the morning to get glass and resin ordered. Just bought the coosa and will be picking it up in a couple weeks.

Tom suggested that silver tip is the way to go and Jeff confirmed that it is a premium product but encouraged me to ask all of you again if anyone had experience/opinions of the marinepoxy sold here as well. It is close to half the price and if it would work basically as well I could sure use the savings after buying all that coosa! Let me know what you think if you have ever used either of these two products.

Would there be any issue with buying enough 1708 for the tunnel and using 1700 for everything else or is this just unnecessary complication.

fallguy1000
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Re: Sea Ox Rebuild

Post by fallguy1000 »

You can build the tunnel with 1700, but 1708 is nicer to keep shapes of dry fabric cutouts. Go to four inside, one outside and a tape on the outside overlapping the darted glass.

You will need 1708 or 1208 tabbing tapes to tab stringers to hull and tunnel to transom inside, etc.

Marinepoxy will work. You'll need to watch for any blush working outside. Silvertip has never blushed for me in say 300? Gallons...225? In my boat 75 gallons waste in vac work? I screwed up and shudda gone cheaper epoxy. Too late.
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VT_Jeff
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Re: Sea Ox Rebuild

Post by VT_Jeff »

Dipper wrote: Mon May 24, 2021 6:20 pm Just got off the phone with Jeff and will be speaking with Reid in the morning to get glass and resin ordered. Just bought the coosa and will be picking it up in a couple weeks.

Tom suggested that silver tip is the way to go and Jeff confirmed that it is a premium product but encouraged me to ask all of you again if anyone had experience/opinions of the marinepoxy sold here as well. It is close to half the price and if it would work basically as well I could sure use the savings after buying all that coosa! Let me know what you think if you have ever used either of these two products.

Would there be any issue with buying enough 1708 for the tunnel and using 1700 for everything else or is this just unnecessary complication.
You may not realize all the benefits of the silvertip in your use case. I'd go with the marinepoxy if there is no technical limitation.
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Fuzz
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Re: Sea Ox Rebuild

Post by Fuzz »

I have used a bunch of both Marine epoxy and System Three. For most things they are the same. If you are doing foam core you need the better proprieties of System3 but it makes no difference if using plywood or going all glass. One thing is when going from one epoxy to another you need to make sure you have a full cure. So if going from Marine epoxy to QuickFair you need to wait for maybe 4-5 days depending on temps. Marine epoxy hardner in fast or medium will blush at times so you must watch for it. No problem to scrub blush off with warm water and dawn.
As for the 1700-1708 deal you just need to try some of both. Some folks use one or the other and some mix and match. For me when using epoxy it is 1700, but that is me.

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