Transom Troubles (Another Gluvit Question)

[Mojo^]

Can Gluvit be used on the outside of a transom as well as the inside? I have a good many pin holes on both sides of my transom (1442 Grumman jon boat manufactured in 1988). I suspect that pressure treated wood was used for the core and I will attempt to replace it with plywood coated with fiberglass resin. The boat was used in brackish water conditions so I suppose some of the corrosion could be from salt water. Anyway, after I replace the core I would like to seal the entire transom with Gluvit and then paint the entire boat. Can Gluvit be used in such a manner? Any input will be greatly appreciated.

 

[Woodonglass]

Re: Another Gluvit Question

Re: Another Gluvit Question

Yep, done all the time. NO UV protection so paint IS required.

 

[Mojo^]

Re: Another Gluvit Question

Re: Another Gluvit Question

Thanks for the reply. Can Steelflex be applied over Gluvit or would a marine polyurethane be more appropriate? Does primer need to be applied to the cured Gluvit coating in order for paint to properly adhere or does it simply need to have it's surface abraded? I don't have the capability to apply paint with a spray gun and will have to use a roller so I would like to use something that will be as durable as possible yet produce a decent appearance. I read where all loose material must be removed for Gluvit to be properly applied but does this requirement apply to cured paint? I guess what I am asking is, can Gluvit be applied over paint or does it need to be down to bare metal?

 

[Woodonglass]

Re: Another Gluvit Question

Re: Another Gluvit Question

They are SIMILAR products but I would think you would use one or the other NOT both. Either way you need to remove the paint to BARE aluminum if you want to ensure proper adhesion.

 

[Huron Angler]

Re: Another Gluvit Question

Re: Another Gluvit Question

I think it would be more cost-effective to use normal epoxy resin rather than Gluvit.

If it is being adhered to aluminum then Gluvit is great to use since it has Zinc Chromate in it.

 

[Mojo^]

Re: Another Gluvit Question

Re: Another Gluvit Question

Okay, Gluvit over a bare metal transom and then paint the entire boat inside and out. I was thinking steelflex was more like a thick, heavy duty paint but it appears that it is an epoxy as well. I like the fact that Gluvit will seep and remains somewhat flexible where steelflex, despite it's name, cures to a hard and rigid finish but I was trying to get sealing and a paint-like finish all in one application without having to take the entire boat down to bare metal. Perhaps I should consider using JB Weld Marine or 3M 5200 with a spatula to seal the pin holes caused by corrosion and then steelflex the whole thing but this sounds like a rinky-dink solution and not very permanent. Thoughts?

 

[Mojo^]

Re: Another Gluvit Question

Re: Another Gluvit Question

I think it would be more cost-effective to use normal epoxy resin rather than Gluvit.

If it is being adhered to aluminum then Gluvit is great to use since it has Zinc Chromate in it.

What kind (brand/product) of "normal epoxy resin"?

 

[Huron Angler]

Re: Another Gluvit Question

Re: Another Gluvit Question

Okay, Gluvit over a bare metal transom and then paint the entire boat inside and out. I was thinking steelflex was more like a thick, heavy duty paint but it appears that it is an epoxy as well. I like the fact that Gluvit will seep and remains somewhat flexible where steelflex, despite it's name, cures to a hard and rigid finish but I was trying to get sealing and a paint-like finish all in one application without having to take the entire boat down to bare metal. Perhaps I should consider using JB Weld Marine or 3M 5200 with a spatula to seal the pin holes caused by corrosion and then steelflex the whole thing but this sounds like a rinky-dink solution and not very permanent. Thoughts?

Normaly Gluvit is only used on the bare aluminum hull, to seal seams and rivets.

Folks have used it for sealing wood also, and it will work great, but costs more then epoxy usually.

What kind (brand/product) of "normal epoxy resin"?

I have always gone with clarkcraft.com for my epoxy resin, other have been happy with uscomposites also.

To waterproof and add strength you can seal the transom plywood with the resin, or add fiberglass mat or cloth as well.

 

[jigngrub]

Re: Another Gluvit Question

Re: Another Gluvit Question

Loc-tite has a marine grade epoxy (available at Wally world) that will setup under water. I've used it to patch screw holse in my transom from different transducer mounts.

 

[Mojo^]

Re: Another Gluvit Question

Re: Another Gluvit Question

I need to post some pictures. It may be that the transom is merely filled with foam rather than plywood. I won't know for certain until I can get it torn out. This means removing the motor, cutting-out both support enclosures containing floatation foam (between transom and rear bench seat), drilling out rivets and removing bolts. Not a job for the faint of heart but it's got to be done. I won't know the extent of the corrosion until I can get inside the transom and behind the support enclosures to see what is what. There are two major areas of pitting/pin holes that received a half-way repair job by the previous owner using what appears to be 3M marine caulk (white) and JB Weld on each side of the exterior surface of the transom under each of the handles. The pin holes leaked a good bit (one pee'd) when I filled the boat with water last weekend to check for leaks. The white caulk covers bolt heads that pass through the transom. There is corrosion around the bolt holes and some of them have pulled through. The pin holes were merely smoothed over with JB Weld. I just need to get all of this stuff properly repaired and I'm not sure what to do or how to go about it but I feel certain that it can be done provided that the corrosion isn't too extensive.
http://s2.photobucket.com/albums/y26/Mojo478/Grumman Project/?action=view&current=Grumm1.jpg
http://s2.photobucket.com/albums/y26/Mojo478/Grumman Project/?action=view&current=Grumm6.jpg

 

[Woodonglass]

Re: Another Gluvit Question

Re: Another Gluvit Question

One things, for certain, your transom is NOT filled with foam. It is wood, or some sort of composite material. It has to be strong to support the weight and torsion of the motor. Your description of removal sounds correct. Just need to get er dun!!!!!

 

[Mojo^]

Re: Another Gluvit Question

Re: Another Gluvit Question

Indeed, it is wood. Looks to be a 2"x12". Yesterday I used a pick to probe around the bolt holes that are pulling through and the inner material sandwiched inside was coming out something akin to old foam or possibly wet sawdust so that tells me there is at least some water damage inside, to what extent I can't tell. I'm going to start with removing the enclosures with floatation foam to see what I can get to with them out of the way. If it's not too bad I may just leave the wood inside and try to seal both sides of the aluminum skin. If there are large areas that feels soft then I may have to go all the way. I'd like to avoid that if at all possible but I do like to do things right. I just came in from the backyard and counted 32 rivets that will have to come out and I suck at drilling out rivets so I'll CAREFULLY grind the heads down with a Dremal and then tap them out. I won't be able to reinstall the same BB head rivets and will have to go with a closed-end pop rivet instead.

Does anyone see any problems with leaving those enclosures out if I adequately brace the transom? That looks to be an ideal spot for a gas tank and batteries. I think those enclosures are installed to allow the boat to handle a little higher horsepower motor. It has a 25 on it now which may be a little much without adequate bracing of some sort.

 

[Woodonglass]

Re: Another Gluvit Question

Re: Another Gluvit Question

Those boxes, If they are indeed filled with foam, are probably designed more for the purpose of giving the boat some added floatation. You could remove the boxes and add some transom braces for added motor support. Based on your description of the condition of your transom I STRONGLY advise you to TOTALLY REPLACE it. It IS one of the most important structural components of your boat and you do NOT want to skimp when it comes to it's structural integrity.

 

[Mojo^]

Re: Transom Troubles (Another Gluvit Question)

I can only replace the inner sandwiched material (wood) as the aluminum skin is welded to the hull. Attempting to replace the aluminum structure would be cost prohibitive. I've considered adding additional layers of 6062 T6 with a fillet and fay seal using MIL-S-8802. We'll have to see how it goes this weekend. If it's too extensive, I will abandon the project and sell the boat for scrap metal.:facepalm:

 

[Woodonglass]

Re: Transom Troubles (Another Gluvit Question)

Sorry, I meant Totally replace the Inner core wood.

 

[Mojo^]

Re: Transom Troubles (Another Gluvit Question)

The old transom core has been removed (it was pressure treated which caused the galvanic corrosion). A new transom has been made using two layers of 3/4" exterior plywood bonded together with PL Premium. I'm now ready to seal the new core and was wondering if Gluvit or AeroMarine 300/21 Epoxy Resin would be basically the same thing and equally effective at sealing the transom wooden core prior to installation. Thoughts or opinions welcomed.

 

[Woodonglass]

Re: Transom Troubles (Another Gluvit Question)

Personally, I'd use the cheaper. Gluvit is expensive. There are a LOT cheaper epoxies that would work just as well. OR you could just use the Poly resin and Mat that you can buy at Lowes or HD. $30.00 and you're good to go. You MUST use the mat though. Poly resin by itself will dry brittle. NO GOOD. Pay Very CLOSE attention to the edges and Make SURE to pre-drill and Coat all holes you make with epoxy. You can use the 5 Min mix up kind.

 

[Mojo^]

Re: Transom Troubles (Another Gluvit Question)

I want to use as many common materials as possible for simplicity and not contribute to the ever growing mountain of clutter in my garage. I am thinking of using Gluvit elsewhere so if I am going to buy it anyway I might as well just get more of it. However, I remain open to options. If I were to use another brand of epoxy resin as a sealer, whats brands would you guys recommend?

 

[Woodonglass]

Re: Transom Troubles (Another Gluvit Question)

I like their products and a LOT of the guys on here use it too!
www.uscomposites.com

 

[Mojo^]

Re: Transom Troubles (Another Gluvit Question)

Wow, that's what I was looking for. A one-stop-shop. Thanks for the link.

Now, on a separate note. I have removed quite a few solid rivets from the boat. 65 to be exact. Only a dozen or so are below the waterline. I want to reinstall closed-end pop rivets with a sealant of some sort that will not affect the application of Steelflex later on. I was thinking Marine-Tex putty but perhaps I can make my own with the U.S. Composites 635 resin system with cabosil added but then again, maybe with Steelflex being an epoxy in itself I won't need to use a sealer at all. I'm just thinking out-loud. Feel free to bash all crummy ideas.