Wood Glue versus Epoxy

[Jim Dodd]

I've been working on several projects, that involve Water Proof, Wood Glue, at the Wood Shop lately.
Getting my hands coated with a little wood glue.
I let the glue go for a few hours, before washing it off.
Washed right off with cold water.
That got me to thinking, how Epoxy would never wash off, with water, not even with soap.

Why would I rely on Wood glue, to hold things together in a wet environment ?

I know it doesn't matter, so long as things are covered in epoxy and cloth, like strips.
But for things like decks, stems, and gunnels, I'd think Epoxy would be far superior !

Just my Country Boy Observation.

Jim

 

[Glenn MacGrady]

The attached PDF with glue comparison tests performed by Fine Woodworking Magazine has been posted before on this site. For overall average strength in various woodworking joints and with various woods, Titebond III came in first, just squeaking ahead of epoxy.

 

[Gamma1214]

I worry about developing sensitivity to epoxy so I'm extremely careful about skin contact (I seem to still get some) and use epoxy sparingly.

I've taken to gluing seat & thwart laminations (I don't make decks) but I do use epoxy where the piece will experience more constant water contact (like paddles).

 

[ppine]

No contest. Wear plastic gloves. I used to build sail boats for a living. A long time ago we just washed our hands in acetone. Now I am much more careful .

 

[Cruiser]

I worry about developing sensitivity to epoxy so I'm extremely careful about skin contact (I seem to still get some) and use epoxy sparingly.

I've taken to gluing seat & thwart laminations (I don't make decks) but I do use epoxy where the piece will experience more constant water contact (like paddles).

If you are worried about developing or have sensitivity, then cleanup of any skin contact is also important ... the recommendation is to use waterless handcleaner, I keep a jar in the shop just for that purpose. Apparently solvents such as water will help it transit through the skin.

Personally, I keep a few glues and epoxy on hand in the shop ... each one has strength and weaknesses, for the most part almost any glues are strong enough for almost any wood joinery. Collectively we makers tend to overkill on glue strength.

I wince when I read someone is gluing strips with TB III, it is so far beyond overkill and presents real issues at cleanup time. It is waterproof and has a light chocolate colour, but it never gets hard and is so strong that if you pull it chunks of wood come out, and if you try to sand it, ti is a bit elastic and creates issues with removal. However, If I am laminating, say Maple table legs ... it would be my go to .... the closed pore structure of maple is no match for TB III, while I have had epoxy fail to get a real good bond. The elastic nature it has though, makes it not a good choice for something like bent lamination's.

I think it is really important to understand the strengths and weaknesses of the various glues we have ... they are just as important to a project as the tools we use to dimension the woods pieces.

Brian

 

[dogbrain]

I have used TB III on all my canoe builds, paddles etc. and never had any issues. It has the longest open time and most importantly is rated for use at the lowest temperature of all 3, which means I don't have to heat up the shop as much. I am pretty good about using the right amount of glue, so squeeze out isn't an issue and I am good about wiping any off as I go.

Mark

 

[Cruiser]

I have used TB III on all my canoe builds, paddles etc. and never had any issues. It has the longest open time and most importantly is rated for use at the lowest temperature of all 3, which means I don't have to heat up the shop as much. I am pretty good about using the right amount of glue, so squeeze out isn't an issue and I am good about wiping any off as I go.

Mark

If you have good habits, like cleaning up excess glue it is great, I always caution folks because "cleaning up excess glue" seems to be a foreign concept to some.

For stripping I am a fan of the LePages Express, you get just enough time for putting on a strip, 10 minute setup and a 37 F chalk Temp .... if you can get it, it is worth a try IMO.

 

[Jim Dodd]

Thanks Glenn, for sharing that test !

Though it didn't make a comparison of water soaking, I still wonder, if say Titebond III, was compared to epoxy, in that respect.

Paddles are usually coated with a Polyurethane, or such, to water proof the blade. So that would change the effect.

Maybe take laminated layers, of bare wood, one with Titebond III, and one with epoxy, and steam them, or simply soak in water, say a day or two ?
I know, which of the two is harder to clean off my hands.

As many use Titebond III to laminate stems, I wonder, if it's equal to epoxy ?

I know Bow builders use epoxy to laminate bow limbs. But again that is different than canoe building.

Jim

I have used TB III on all my canoe builds, paddles etc. and never had any issues. It has the longest open time and most importantly is rated for use at the lowest temperature of all 3, which means I don't have to heat up the shop as much. I am pretty good about using the right amount of glue, so squeeze out isn't an issue and I am good about wiping any off as I go.

Mark

That there is a good testimony !

Thanks Mark

Jim

 

[Jim Dodd]

If you are worried about developing or have sensitivity, then cleanup of any skin contact is also important ... the recommendation is to use waterless handcleaner, I keep a jar in the shop just for that purpose. Apparently solvents such as water will help it transit through the skin.

Personally, I keep a few glues and epoxy on hand in the shop ... each one has strength and weaknesses, for the most part almost any glues are strong enough for almost any wood joinery. Collectively we makers tend to overkill on glue strength.

I wince when I read someone is gluing strips with TB III, it is so far beyond overkill and presents real issues at cleanup time. It is waterproof and has a light chocolate colour, but it never gets hard and is so strong that if you pull it chunks of wood come out, and if you try to sand it, ti is a bit elastic and creates issues with removal. However, If I am laminating, say Maple table legs ... it would be my go to .... the closed pore structure of maple is no match for TB III, while I have had epoxy fail to get a real good bond. The elastic nature it has though, makes it not a good choice for something like bent lamination's.

I think it is really important to understand the strengths and weaknesses of the various glues we have ... they are just as important to a project as the tools we use to dimension the woods pieces.

Brian

I have also felt that Titebond III, to be softer, and more difficult to sand.
Yes, more flexible, so maybe good and bad. Just not perfect.

Agreed.

Jim

 

[dogbrain]

For stripping I am a fan of the LePages Express, you get just enough time for putting on a strip, 10 minute setup and a 37 F chalk Temp .... if you can get it, it is worth a try IMO.

Thanks, this sounds good. I see it's available at Canadian Tire. I'll grab some on my next trip north.

 

[memaquay]

I've been on the titebond 3 express for a couple of years now. Last year, my students built over 30 paddles with it. this year we are at around 20 more. I ran out in January, and the truck carrying my amazon order must have crashed, because it got lost, so it took me over a month to re-supply. I was at the tail end of laminating the last few paddles with the kids, so I had to switch back to epoxy. I followed the formula I used for years, coating the wood first with un-thickened epoxy and then following it up with thickened stuff. I can tell you, I didn't miss that process. I also got to thinking, the titebond is less hazardous than the epoxy when working with kids, plus I don't have to supervise the whole mixing part to make sure the ratio is correct.

It's early days, but so far none of the paddles have delaminated.

I've also used titebond 3 for scarfing gunwales, and I used it on my last stripper build to glue the strips on. I haven't found much difference in sanding between it and regular glue, maybe tougher if one is too generous with the glue.

My students glued up both sets of stems for the modified pal this week. Kids either go completely overboard with glue amounts, or hardly put any on, it's hard to get them to get it just right. In this case, they went completely overboard, there was glue everywhere. However, the stems are rock solid, no flex at all, and perfectly maintained their shape.

I do some guitar repair for the music class too. The guitars are quite cheap, and with our dry winters, it is not uncommon for bridges to separate and start to lift off. On an expensive guitar, they usually use some kind of animal glue, or something that can be heated to release the bond at a later date if there are problems again. Titebond 3 was not recommended, but I used it anyway, the guitars were around 150 bucks new. Those bridges will never move again, I'm sure of that, lol.

I remember when gorilla glue first came out, the foaming kind. I was told it was the new replacement for epoxy, so I used it quite a bit, due to the 100 percent waterproof claim. Overtime, I came to see it was no good. I've had a few scarf joints on gunwales delaminate, as well as paddle delaminations.

Anyway, I guess time will tell with titebond three, but so far I'm a big fan.

 

[Cruiser]

TB III is a good product and has it's pluses like being pretty much the strongest glue available, waterproof, reasonable open time and easy use (literally point and shoot). Mem if you haven't tried making a small puddle of TB III and let it dry (make sure to use a smooth non porous surface so you can peel it off), you should try that. The final product is "bendy" like plastic, chocolate brown in colour and it will never lose that elasticity and it is strong as heck. Probably why it holds so well, it is not susceptible to shock. Might make a good "show and tell" object in the shop.

IMO 3 things that make epoxy stand out in it's own category are 1) complete gap filling capability 2) full tinting 3) very long open time.
If I do a 36" long skarf in a 2" x 8" , that cut line will never be perfect, so saturating and buttering with thickened epoxy will fill the gaps and achieve a full strength joint, no glue can do that. I expect some flack for that statement, but glues just don't have the gap filling feature ... they will bond the pieces and likely very well, but never to extent that epoxy will. When joining you can tint the epoxy to blend or stand out in a joint, when doing paddles, I will intentionally use dark tinted epoxy as a joiner to make the edge "pop" a little. When attaching something like a gunnel, all these points come into play, and epoxy gives you lots of time and allows custom tinting to match the colours.

The 2 main things I am cautious about with epoxy is the potential toxicity/sensitivity and weight. Epoxy is heavy and once mixed it doesn't change weight, it soaks into the wood and hardens. The joint is very strong, gap filled etc. but what remains in the joint, is also much heavier than a similar glue joint. Glue does not penetrate like epoxy and lightens a lot as it sets up (solvents coming off). So if you have a highly jointed piece of work, gluing will be measurably heavier using epoxy compared to something like TB III.

So if you are building something weight sensitive, like a canoe, where weight is a concern (at least it is for me), then epoxy use is carefully considered and glue is used where it is the best choice and epoxy used where it is the best choice .... based on the build needs.

 

[Jim Dodd]

Gunnels get a lot of stress, but paddles, the most, in my thinking.

If Titebond III, has worked for others, on paddles, and gunnels ? I'd say stick with it ! It would be a lot easier to work with, than epoxy, that's for sure !
I'll still stick with epoxy, for gunnel lamination, and if I decide to make a paddle.

I just never trusted something, that states it's waterproof, but easily cleans up with water.

Jim