Sealing bolt holes in transom ?

[Clint KY]

I tried to do a search, but could not get specific enough to get an answer. I have a 1964 Ouachita 10' jon. The transom was two layers of 1/4" plywood, that was so rotted, I took out with my bare hands. Cut 5 bolts out with my side grinder. Four were up top, close to the gunnels, that held the two lift handles, so I don't think they will cause any problems. BUT - there is one that will most likely be below the water line. I plan to thoroughly seal the 1/2" plywood I am using.

Two questions:
1) What should I use to seal the wood?
2) What can I use to seal around the one bolt that will most likely be under the water line?

Thanks

 

[poorthang]

fill it full of fiberglass resin and be done with it. the transom ties into te gunwals and gives stability to the entire boat. dont pass by that area.

 

[BAY BEAGLE]

I just completed the task that You are starting on. In regards to sealing the wood; I used OLD TIMERS FORMULA: you can find info in the search box or Google. I used a series of 100% Spar after the series of Old Timers.

In regards to Your bolt - look at 3M 5200 MARINE
If You have holes; I chose West Systems 610 to fill them.

Enjoy

 

[DaleH]

Fhugghedabout using 3M 5200 and that Old Timers formula ... if you want it done ONCE, done right and truly waterproof ... use epoxy.

Simple done ... see here for full DIY tutorial and pictures: https://forum.tinboats.net/viewtopic.php?t=47405

 

[JLeephoto]

Fhugghedabout using 3M 5200 and that Old Timers formula ... if you want it done ONCE, done right and truly waterproof ... use epoxy.

Simple done ... see here for full DIY tutorial and pictures: https://forum.tinboats.net/viewtopic.php?t=47405

To seal plywood multiple coats of penetrating epoxy making sure to get edges. Raka has good kits/prices. Be sure to read the details on the catalyst choices. http://www.raka.com/epoxy.html

Lots of rigging shops use 5200 to seal bolt holes and it seems to work reasonably well but what DaleH said is how to do it right according to most boat builders. Ie: Overdrill holes, fill with epoxy, redrill center of epoxy plug for bolts. This way there’s no way you’re getting water in the wood.


Sent from my iPhone using Tapatalk Pro

 

[thill]

If you are just sealing under ONE bolt head, 4200 or even regular silicone will work just fine.

Put the silicone on the shaft of the screw, and then push/twist it into place. Lightly tighten it down and wipe the excess off. After the silicone cures, a day or 2 later, tighten the bolt fully, and you won't have any problems. That creates a compression seal along with the original adhesive seal. Just make sure the area is clean before applying.

 

[Iammichael6499]

In other words … you have a zillion options for sealing the wood and the hole(s). Which ones are the best? Almost all of the above will work so I’d pick the ones that fit your skill sets and budget the best.

 

[Iammichael6499]

BTW, I had a 10’ aluminum flat bottom many years ago. I thought I would use it recovering ducks that floated into deep water (ponds mostly) but I soon found out it was “too unstable“ for me. If I made a mistake in that boat I went swimming. I sold it to 2 ladies, both over 200 lbs, who wanted it for perch fishing. Despite my warnings they wouldn’t be deterred from buying it. I would have loved to have been there when they pushed off from the bank the first time.

 

[GrogHog]

I tried to do a search, but could not get specific enough to get an answer. I have a 1964 Ouachita 10' jon. The transom was two layers of 1/4" plywood, that was so rotted, I took out with my bare hands. Cut 5 bolts out with my side grinder. Four were up top, close to the gunnels, that held the two lift handles, so I don't think they will cause any problems. BUT - there is one that will most likely be below the water line. I plan to thoroughly seal the 1/2" plywood I am using.

Two questions:
1) What should I use to seal the wood?
2) What can I use to seal around the one bolt that will most likely be under the water line?

Thanks

3M 5200 or 5100 if u have time for curing. only thing to use in Fla,

 

[Douglasdzaster]

Another vote for epoxy. I just built a new floor in mine and used Total boat penetrating epoxy. Fallow the directions. I applied the first coat diluted with equal part acetone and it really soaked in. Then two more (overkill) without diluting. Be sure and hit the edges every time you want them sealed on plywood for sure. This stuff says it even makes rotten wood solid even if you have to inject it.
And of course 5200. Be sure to have something between the aluminum and the bolt hardware and you won’t have to worry about galvanic corrosion. Especially if you’re in saltwater. I’ve been rebuilding my boat and ran across a lot of it. I found hardware from stainless steel to regular bolts and screws. I figured out real quick my boat had been in saltwater. When I’m finished it’s freshwater only.
That all being said most of these guys on the forum have a lot more wisdom about tin boats than I. I’m just sharing my experience and without all the help from them I wouldn’t know what I do now.
Good luck and have fun with it.
Edit: I went back and read the other replies and I like the idea of skipping the 5200 and going with the way they said to epoxy the holes. Dale H seems to always know the best thing to do. He has helped me a lot. I know when I get to redoing my transom I’ll be using epoxy now.

 

[airshot]

If your going to be real serious about it lasting a long time, look xarefully at the bolts you will use. You need real SS bolts, not the home depot version of cheap partial SS bolts. Take along a magnet, it it attaches in any way to the bolts, leave them alone and getvtrue SS bolts, the magnet will not be attracted to the bolt in any way, now you dont need to worry about the bolts getting eaten up. Pure SS wont react to aluminum.

 

[cyclops2]

S S is made in both magnetic and non-magnetic metal.

 

[Mudbugger]

If your going to be real serious about it lasting a long time, look xarefully at the bolts you will use. You need real SS bolts, not the home depot version of cheap partial SS bolts. Take along a magnet, it it attaches in any way to the bolts, leave them alone and getvtrue SS bolts, the magnet will not be attracted to the bolt in any way, now you dont need to worry about the bolts getting eaten up. Pure SS wont react to aluminum.

Stainless steel is offered in several classes, most common are the 300 and 400 series. 300 is nonmagnetic and more stain resistant, but softer and can not be hardened.
400 is magnetic, not as stain resistant, but harder and stronger.
Most of the SS measuring tools, calipers, micrometers ETC are magnetic.

 

[AlanT]

316 stainless steel is recommended for marine environments. 304 is not a bad choice. Some information at the link below on 304 vs 316. The more corrosion resistance, the less magnetic. Neither 304 or 316 are magnetic.

316 stainless steel differs from 304 stainless steel because it contains 3% molybdenum. Because of this corrosion resistance increases and many other properties improve such as resistance in pitting in chloride ion solution and also increases strength at high temperature.

https://www.ambicasteels.com/blog/stainless-steel-grade-304-vs-316-importance-and-differentiation/

 

[cyclops2]

Stainless Steel gains strength only if steel is added to the mix. So the magnetic S S has more steel in it. I have never had cheap S S bolts fail in 70 years of using them.