Floor repair:epoxy vs resin

[TomW]

I'm faced with floor rot in my in my "new" '67 Overlander. I have worked with fiberglass mat and resin before in several different types of repairs, and have a certain comfort level with the materials already established.

On the other hand, I use 2-part epoxy, & JB Weld all the time for general repairs on small parts (because it comes in small tubes), and thoroughly appreciate the virutes of both. All the posts on floor repair I have read seem to recommend "Rot Doctor" or equivalent for floor repairs. I do not have ready access to large quantities (a quart or more) of 2-part epoxy (apparently the main ingredient of store-bought floor repair), although I could mail-order it.

Does anyone have thoughts, one way or the other, on fiberglass resin versus epoxy for floor repair? This forum has been a great source of insight, and I hope someone has thought of this before.

Thanks!

[Navigator]

T.C.
Stick with the epoxy only because of the mechanics of the repair.
Most likely you will want to remove as much of the rotted wood, then seal with epoxy.
Now comes the task of filling in the hole, then after cure, sand flush with the floor.
Glass IMHO will only complicate the leveling aspect of the job.
Dick

[j54mark]

The main advantage of penetrating epoxy (Rot Doctor, et. al.) is that it gets into the wood matix and forms a structurally sound material. Fiberglass and resin is simply going to become a coating resting on top of rotten wood.

Mark

[TomW]

Actually, I was thinking about just using the fiberglass resin for starters instead of epoxy, unless there was an obvious reason to add cloth/mat to the void.

Does this alter anyone's answer?

Thanks,
Tom

[j54mark]

My experience with fiberglass resins is somewhat limited, but what little I have used was too viscuous to penetrate very deeply into wood. The power of Rot Doctor to penetrate has to be seen to be believed. How far and how much resin you can get into the wood is clearly going to be the key.

Mark

[whistler]

I would not use fiberglass resin, like Mark replied it will only penetrate the wood about 1/4". This will not give you the soild surface you want.
Gary

[thenewkid64]

I have used both.

I first used the rot doctor stuff with great results. It stabilized the wood and added strength back where there was little strength before. That left me with voids. The floor sounded very hollow in spots. there was also some spots where the fibers of the wood were quite thin. I mixed the fiberglass resin and poured it into the area until it was level with the surrounding floor. I will admit it took some time to cure, but the floor is rock solid and I have no qualms about the repair. The fiberglass resin was without glass. I just mixed it and poured it in on a cool evening so it would cure slowly and flow for a long time.

[59toaster]

I used the resin but I was using it to seal a new wood floor not to repair. Product like Rot Doc is what you want as long as it:
1. surface damage
2. doesn't involve any structural items.
3. limited area

You don't want to try to patch 4 square feet rotted half way through and down the main isle of the coach.

small area under the reefer is the type of repairs you want to do with this product.

If it's a large area then your much better off in the long run to replace the wood. This is especially true if you have a long strip of rot along a wall it may be more rot then you think and it is comprimizing the strength of the coach.

Try West Marine http://www.westmarine.com/ They have stores all over as well as mail order

[markdoane]

You could also try low viscosity epoxy.System 3

[CanoeStream]

Well, we know it isn't "dry rot." (No such thing!)

59toaster and markdoane are in the long process of floor replacement. I've discussed various aspects of epoxy use on this page of their long thread.

With the possible exception of "cold molding" a boat hull with veneers impregnated at each layer, I cannot imagine any situation where epoxy would rot-proof the subsurface volume of your floor. In boatbuilding it too often serves to keep moisture inside a piece of wood and accelerates structural failure. You should start with totally dry floors and be able to treat every through-hole you can't keep dry after completion. Search on the word Clamshell for a good solution to a rear bath floor section being bad.

Epoxy might be your second job. More to the point would be to control all sources of moisture that led to the problem in the first place. Replace all window, door and access door (battery) weather stripping. Replace roof vent gaskets. Are you absolutely certain of the soundness of the plumbing? And on and on...

Any Rot-Doctored or epoxied patching may be a temporary measure until you can plan or budget a floor replacement. So don't tape or 'poxy a fillet between the floor and the shell -- you'll never get it apart without a mess.

[74Argosy24MH]

There was a member who posted about using fiberglass to fill relatively small holes in the floor. The gist of it was to remove all the bad wood and cut thin slots on opposite sides of the hole. He put a thin rods in the slots (it will have to be a tight enough fit for the rod to stay in by itself). He then used mat and resin to fill to level with the floor and set the rod into the wood.

If this is close to what you are considering you will need the mat, it will be much stronger and last a lot longer than just the resin.

John

[Navigator]

The epoxy resin formulations designed to restore rotten wood contain VERY EXPENSIVE surfactants and wetting agents which through cappillary action carry the epoxy deep into the substrate.
Polyester resins on the other hand are designed for adhesion, UV resistance, and leveling for a smooth surface, none of which would be beneficial to restoring bad wood. Polyester does not penetrate to the level desired.
Dick