Protecting drain hole while fiberglassing drift boat bottom

I am getting ready to fiberglass the bottom of my Keith Steele drift boat and I can't figure out how to keep my drain plug hole clear while applying epoxy, fiberglass and epoxy with graphite. I was thinking of stuffing with a rag, or screwing in plug with a plastic bag wrap. I assume whatever I do I will need to remove it and clean threads with thinner after epoxy thickens. Any suggestions?

I have attached photo instead of inbedding it because I just have my iPad today. This photo is before I filled in holes around it with sculptwood.

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Kirk, I am standing by to read the responses.  I am at the very same place and have the same question.  Have you thought about plugging it and glassing over.  I'm not convinced of the need for the drain going forward. I am likely decking my boat and heading the dory direction or maybe a hybrid.

I have a couple questions for you:

What weight glass are you using?

Does your boat have an exterior chine log? and if so, as mine does, are you wrapping the glass over it, and up the sides any?

Thanks, Kevin

Not sure about the sculp wood thing.This is what i would do,first coat neat all over hull let tack then some thickened to fill voids let tack again,neat again then glass and neat to get full wet out when the glass gets to the green stage or just before with a razor cut out the drain follow on the outside edge of it.Once cut use a socket or pipe just a little bigger then the drain ring place on top some plastic with a circle cut out then the socket and just a little weight to hold down the glass insuring a good bond.Once this is all dry or almost dry to touch you can mix your fill coats with a hard to sand filler, apply with small notched trowel and let gravity flatten it out,make sure you dont add too much filler that it wont self level.Lastly, drink a beer and admire the glass like surface.

Just keep the plug in on the first neat and thickened coats,remove for the glass,maybe a little grease on the threads but should be ok as after all is done a little heat will soften the goo in the threads.

Neat=plain warmed epoxy

Green=not quite dry but dry enough the glass will cut without distorting trying to cut it while still wet will distort the glass and make a mess.

Hey Kevin, thats a chine cap. You really dont want to wrap that in glass, its there to get beat up and replaced some day. In the new build, I glassed the sides, then the bottom, then added that chine cap with bedding compound just to seal out water. The top though I`m sealing in even more with varnish while I do the sides and the bottom side (edge) I filled right onto with my last couple coats of epoxy with graphite. The varnish and the epoxy on bottom can get cut to remove the cap. Just to give a idea.

If your chine cap is in really good shape and you want to leave it in place, might want to glass just to it, trimming the glass while its green and finish off the bottom with the epoxy like I did. If its beat up, this would be the time to replace it.

Thanks Mike.  I guess I thought the chine cap was the metal strip that secures to the chine. Thanks for the clarification.  So.... I should remove the wood chine cap, glass over the edge and just up the sides a bit? Then replace the chine cap if I'm so inclined.  I see many boats that don't have one.  I understand its sacrificial... is it reasonable to do without?

How about fabric weight?  One layer of 20 oz+, or several layers w/lighter weight?

Thanks, Kevin

I cant answer all that. The metal strip would be to help protect the chine cap. The chine cap is to protect the boat. You`ll have to do some searches about wrapping a edge with glass, I dont think its recommended.

I didnt wrap mine, I glassed the sides to the bottom of the boat, covering the edge of the bottom plywood and trimmed it off flush with the bottom. Then I glassed the bottom and trimmed it off flush at the glass of the side, on the bottom corner. That made for a nice corner and well sealed with all the epoxy.

I dont think it would be a good idea at all to not have a chine cap, unless your only going to use the boat in small ponds with no rocks.

Weight of glass, again it depends where you are, what water you`ll be on. What I used was 12 oz biax glass, 1/2 dozen coats of epoxy and 2 coats of graphite on the bottom, should work here in Mich but would not hold up to white water and boulders out west. Again do some searches. 20-30oz. sounds in order for white water.

I installed my drains after I glassed but before my last 2 coats of epoxy and graphite. I was just able to brush neatly around my drains, which I installed with 5200 which really sealed them in good. Tungsten`s ideas sound good. You could put some plastic or something in the hole, or the plug if it near flush with the bottom and put a cut circle of clear packing tape over the plug, the epoxy wont stick to the plastic tape and glass over it, trimming the glass with a zacto blade as it is setting up (where it just starts to get stiff). You can always sand the glass after its hard, and/or touch up the hole with resin, you just want to keep it out of the threads of the drain hole.

Thank you tungsten and Mike. Your ideas make sense.

Fiberglass cloth will not cleanly wrap around a 90 degree corner. You frequently end up with a bulge, bubble or gap and basically wasted cloth and epoxy. A sacrificial chine cap will absorb and distribute the stress of an impact over a much greater area. Fiberglass cloth will fracture as it isn't in tension where it has the greatest strength, it is in compression at it's weakest. Fiberglass cloth applied to the outside of the boat is responsible for abrasion resistance. Hence the greatest amount of fiberglass often laminated to the bottom of the boat where the abrasion most often occurs.

A true McKenzie style framed drift boat depends upon the internal framework to support the plywood, providing a mechanism to hold the plywood skin in a "stressed" or tensioned state thus providing strength and resistance to bending. There is an internal "chine" log where the screws that fasten the plywood to the edges of the boat connect. The internal chine log also help disperse the loads that occur when an object is hit.

A stitch and glue doesn't have a chine cap because the internal chine log is replaced with a combination of fiberglass tape, resin and filler partially up each side or along the bottom to again distribute loads caused by impacts and to bond the sides together. The outside of a stitch and glue drift boat is often also covered with fiberglass cloth or tape and epoxy resin, taking the place of the chine cap but isn't sacrificial but must be repaired if hit or damaged.

The most often damaged part on a drift boat irregardless of the material it is constructed of is the chine area. It's where the rubber meets the road so to speak. Dependent upon the skill of the oars person and the waterway being traveled the amount and frequency of damage will vary.

Hope this answers some questions.

Rick N

Thanks everyone for thought and detailed replies. Kirk, I hope I didn't hijack your forum.

Kevin

Kirk

Keep in mind that cured epoxy is fairly easy to soften and remove with heat.

I think the very worst case scenario is you run a pipe tap into the fitting ;)

I know with mine, the plug only ran about half way into the fitting, but then I cut my fittings down so now the plug almost comes to the bottom

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