Epoxy and gluing questions have my project stalled - Help!

[kookenotes]

I am building the Generic Benroy "woodie" with 3/4" oak plywood. Side profiles are cut, sanded, and temporarily installed. My Galley cabinets are built but not finished. With the help and advice from several TNTTT members, including Doug and Becky, I will be sealing the side walls next with epoxy. I purchased the non-blushing product from RAKA and read their instructions. I plan to take the walls off and apply the epoxy on saw horses. Do I apply to all surfaces and end grain including areas that I planned to glue with tightbond or Gorilla glue (floor, spars, and cabinet edges) or do i mask those areas to insure a good wood to wood bond? I am planning 3 coats on both inside and outside surfaces and then plan to finish with Man-of-war spar varnish to achieve the smooth finish and provide UV protection. Am I correct in assuming that I need 3 coats of epoxy on the inside as well as the outside or can I reduce the interior coats and supply the finish with the spar varnish? I think I have over analyzed the next move and need a push to get me under way again. Any information is greatly appreciated. Seasons Greetings to all the great folks on this forum. Thanks, Bill

[aggie79]

Bill,

I hope others would chime in too. Epoxy or any other wood finish for that matter will not make a good bonding surface for glues/adhesives (except for perhaps thickened epoxy.) So, I would mask off the areas where you plan to have wood to wood joints as you stated.

As far as adhesives, you mentioned Titebond and Gorilla Glue. These are great products but require tight fitting joints. If your like most of us, and not a professional carpenter or woodworker, and have joints with greater tolerances, I would recommend using PL Premium as your glue/adhesive.

Take care,
Tom

[doug hodder]

I only epoxy coat out the exterior of the trailer and end grains if exposed on the hatch sides. All the interior is done with a polyurethane clear over dye. If you want to install some sort of item over any epoxy once it's cured...just scuff up the bonding area and use some epoxy for the adhesive, thickened might be best as it won't run. Others opinions may vary. Doug

[Kody]

G'day Kookenotes
If I were doing this construction, I would give all the plywood three coats of epoxy resin to fully seal the surfaces. I would apply at least three or more coats to all the edges and end grain of all the plywood and the timber to be used for the framing. By sealing all the end grain, you can keep out all the water and moisture from seeping into the most vulnerable part of the wood, ie, the end grain. The water and moisture that seeps in is what carries the airborne fungi that create the rot in the wood. For gluing the wood, I would use epoxy thickened with a specific thickener, eg, Cabosil, which is one of the best thickening agents available. When used with the epoxy, the resin will fill any gaps and still retain its strength. A web search for Cabosil will give you all the details you need. After you have finished gluing and screwing, wipe your hands with a rag wet with common white vinegar but do use throw-away rubber gloves when using the Epoxy resin. The vinegar will clear up any spills on the timber or floor before the resin has cured. A screw hole that is in the wrong place can be filled with the thickened resin and when cured, it can re-drilled for a screw to be driven in. With all the edges and end grain sealed with epoxy, I wouldn't use any other glue but the thickened epoxy for joining/gluing all the joints that are under stress. This would be just about all the joints everywhere. Use an epoxy that has a longer curing time to enable you to get everything set up for the gluing process. The longer curing time is obtained by the chemical design of the hardener. A slower curing rate is not obtained by using less hardener. The resin is the same but read the instructions carefully when mixing. It is essential that the proportions of resin and hardener are absolutely exact. This is easy to do if you use a sensitive weighing scale. You may find it an advantage to supplement the screws with monel nails as used in boat building. Keep in mind that once you drive a monel nail halfway into the timber, it will not come out.
IMO, using Titebond or Gorilla Glue is a waste of time and money if you have used Epoxy to seal all the surfaces as these glues are only half as good (if that) as epoxy and Cabosil.

Kody

[Fishingtomatoseed]

As far as adhesives, you mentioned Titebond and Gorilla Glue. These are great products but require tight fitting joints. If your like most of us, and not a professional carpenter or woodworker, and have joints with greater tolerances, I would recommend using PL Premium as your glue/adhesive.

Take care,
Tom

+1 on the PL. Stuff works great.