FWW article on strength of Glues

[Mark Singer]

In the last FWW , there is an interesting article on the strength of different clues. Pva glues did very well! Epoxy was as good and the wood actually failed rather than the glue. Hide glue was approx 80 % as strong... The worst was Gorilla glue or other polyurethanes at only 58 %. That is what I always thought....it is really no surprise ...and I hate the mess. See this older thread..
http://www.sawmillcreek.org/showthread.php?t=3966&page=2&highlight=gorilla+glue

[Jim Becker]

I just got the mag yesterday, but haven't had time to crack the cover. But that article did catch my eye and I look forward to reading it.

[jason lambert]

Read it also it was just what I thought. I actuall signed up on line and you can get the current issue and all the back issues. So if you want info on something just do a search and they usally have a couple of articals it looks like they have stuff several years back. For $4.99 a month it is a nice resource, especally for someone starting out.

[Hank Knight]

I agree Mark. The few times I used Gorilla Glue, I was not impressed and I still haven't gotten the mess cleaned up! The FWW article has given me the last push I needed to throw the stuff in the trash. Thanks FWW.

On another note, I was a little surprised to see that liquid hide glue did as well or better than the hot stuff.

Interesting article.

Hank

[Mark Singer]

I agree Mark. The few times I used Gorilla Glue, I was not impressed and I still haven't gotten the mess cleaned up! The FWW article has given me the last push I needed to throw the stuff in the trash. Thanks FWW.

On another note, I was a little surprised to see that liquid hide glue did as well or better than the hot stuff.

Interesting article.

Hank


In some old post , I mentioned that i thought the strength was about the same....Liqid hide is very good for fixing flaws in the wood surface and does not bother the finish much

[glenn bradley]

I've seen some trick fixes pulled off with Gorilla Glue; none of them had anything to do with WWing. I have a small bottle in the shop but have never found the need to break the seal.

[Bill Jepson]

Something I haven't seen mentioned is that the poly glues are very temperature sensitive too. Particularly LOW temps. Titebond 3 lists 58°F as the minimum temperature. I used some in a cold shop and it failed totally. Gorilla glue is the same. Original Titebond, if it will set up it's fine. The same with TB 2. Epoxys work fine as well. West Systems are familar to me from composite aircraft building, a great product.
Bill Jepson

[Voytek Jarnot]

They tested two PVA glues, but no urea formaldehyde; which is quite disappointing and doesn't make a whole lot of sense.

[Doug Shepard]

I've seen some trick fixes pulled off with Gorilla Glue; none of them had anything to do with WWing. I have a small bottle in the shop but have never found the need to break the seal.

Squeeze that bottle. If it feels crunchy, save yourself the effort of opening it. The shelf life on that stuff aint all that great. I bought a new bottle that had already hardened and have felt a quite a few on the store shelves out of curiousity. About 1/2 had already hardened.

[RickT Harding]

Something I haven't seen mentioned is that the poly glues are very temperature sensitive too. Particularly LOW temps. Titebond 3 lists 58°F as the minimum temperature. I used some in a cold shop and it failed totally. Gorilla glue is the same. Original Titebond, if it will set up it's fine. The same with TB 2. Epoxys work fine as well. West Systems are familar to me from composite aircraft building, a great product.
Bill Jepson

I had the same experience. The temps really need to be 65+ for me to get TB 3 to really work out for me. I need to finish insulating up the garage this summer and that's one big reason.

[Corey Hallagan]

I have always liked the PVA glues myself. I just didn't like the extra mess with Gorilla glue.

PVA Glue Clean Up:

This has always been an issue with these glues. You will see Norm wipe off with damp towel or rag and by doing so he is rubbing the glue into the fibers and you must rely on your sanding to remove it or you will get the Tell Tale glue trail during finishing. I expect we all have had a few of those suprises. I picked this tip up off of a Woodsmith video. Instead of wiping like this... let the squeeze out set up to a (sorry don't mean to be gross :) ) a sticky boogery consistency and then slice it off with a razor blade and then sand the residue left when dry. Much less chance of forcing it into the pours of the wood I am told. Made sense.

I got this tip from a member of another board. He says wipe off the squeeze out like Norm does but spray a 50/50 mixture of water and vinegar prior to drying and there will be no tell/tale glue trail. Don't know if it actually works but plan on trying it out. Anyone try or use this and it works?

Sorry Mark, I didn't mean to take the thread another direction. I just happened to think of this while we were talking about glues.

Corey

[Dave Anderson NH]

Hi Corey, I'd be worried that the water and vinegar would work too well and get down into the joint. When on the extremely rare occasion (Yeah, right:rolleyes: ) when I've had to disassemble a jointed glued with PVA, I use the water/vinegar mix as an aid to soften the glue. It works very well.

[Art Mulder]

In the last FWW , there is an interesting article on the strength of different clues. Pva glues did very well!

Hey, I just finished that article not five minutes ago! :rolleyes:
(usually us Canucks are way behind you in getting mags)

I do wish they'd tested the Lee Valley 2002 GF glue. It's a PVA also, I believe. It has been my main glue for the past 3-4 years, though I also use Titebond II on some occasion.

Anyone know of articles that have compared the different PVA glues? Or are most of them pretty identical?

...art

[Brian Kent]

My last two attempts at Gorilla Glue have messed up the project. One I finally planed down to clean wood. The other, gluing aluminum to oak, I messed up the aluminum finish and the glue still isn't off.

What (besides a gorilla) shoul I use for joining unlike materials like wood and aluminum? Epoxy?

[Jay Keller]

youll want to wear gloves when using the gorrilla glue. It only wears off.

[Jay Keller]

In the last FWW , there is an interesting article on the strength of different clues. Pva glues did very well! Epoxy was as good and the wood actually failed rather than the glue. Hide glue was approx 80 % as strong... The worst was Gorilla glue or other polyurethanes at only 58 %. That is what I always thought....it is really no surprise ...and I hate the mess. See this older thread..
http://www.sawmillcreek.org/showthread.php?t=3966&page=2&highlight=gorilla+glue


what is pva glue. The link goes to a thread, not an article. Is there an article to read?

[Corey Hallagan]

what is pva glue. The link goes to a thread, not an article. Is there an article to read?

Jay, see this link:

http://www.thistothat.com/glue/pva.shtml

Corey

[Kim Spence]

what is pva glue. The link goes to a thread, not an article. Is there an article to read?
PVA = Polyvinyl Acetate, or standard Yellow or White woodworking glues (Titebond, Elmers, the like).

The thread is a discussion of Polyurethane glues vs PVA glues.

The new article about glues is in the latest FWW.

[Andrew Williams]

I'd like to know what sort of hide glue they were using..Hot?, liquid bottled?, which gram strength and how was it applied...

[Jay Keller]

Jay, see this link:

http://www.thistothat.com/glue/pva.shtml

Corey

Thanks. Thats very interesting article. I tried the gorilla glue and didnt like it because its so messy but it does expand so it has its applications. What is the long setting glue I see mentioned on David Marks show so often for complicated glue-ups? The gorrilla glues says it sets up in 1/2 hour.

[Per Swenson]

I gotta add a little here....

I 'am a tite bond three man= pva.

For your basic assembly's.

Urea For time.

Epoxies on moldings.

But when it comes to shear holding power on darn near anything...

There is one poly I believe to be invincible.

PL premium polyurethane adhesive.

Just last week I returned to a job I did 21 years ago,

stilled glued up tight, outside and exposed to the elements.

Per

[Cliff Rohrabacher]

that moisture cure polyurethane adhesive Glue is my GO TO glue in only two situations:
1.) when gluing a polymer to wood and for whatever reason contact cement won't do it.
2.) when gluing end grain to something and all I really want is to seal the end grain and a little adhesion is good.

That said I wonder if the following wouldn't be a good idea for end grain apps':

End grain glue up in 2 stages: first stage: seal the end grain with epoxy. Second stage: sand and re-apply epoxy and make the glue joint.

Any one ever tried that?

[Martin Shupe]

I'd like to know what sort of hide glue they were using..Hot?, liquid bottled?, which gram strength and how was it applied...

They used Old Brown Glue, which I use and like a lot. They compared it to hot hide glue, and I was surprised to see that they were statistically similar in strength.

I use Old Brown Glue instead of PVA, so I don't have to worry about messing up my finish.

[Brad Naylor]

A feature of PU glues which no-one has yet mentioned is it's contraceptive qualities.

A day using that stuff in the shop and SWMBO will scream 'You're not coming near me with those hands!':D

And it takes a week to wear off...

[Carl Eyman]

Remember Bob's posting relative to which glues can be re-glued? If I remember correctly only epoxy, hide, and plastic resin could be re-glued to itself if the joint failed. Now I don't like the idea of contemplating a joint failure, but in the 200 years some of our early American cabinetmakers have had pieces survive, there are bound to be some failures occur.

One of my most ambitious projects has polyurethane glue (Gorrilla) in a ctitical joint. Hopefully, the mechanical aspects of that joint will save it.
Well, at 85 I don't have to worry very long about it.

[Dennis Peacock]

In some old post , I mentioned that i thought the strength was about the same....Liqid hide is very good for fixing flaws in the wood surface and does not bother the finish much

Yup....I use a lot of liquid hide glue. I like it and guess what.....no glue stains anywhere because this stuff will clean up nicely with warm water.

I even tried to take a glue joint apart by saturating it with water for about 2 hours. It never would come apart......it's still stuck together today. :)

[Alfred Clem]

On the other hand (no pun intended), I use Gorilla Glue when cementing brass tubes into drilled pen blanks. The stuff does a good job bonding metal to wood. But I sure wear rubber gloves when handling Gorilla Glue. Otherwise, it stains the skin like crazy. Even acetone will not remove the stains on my fingers although it does remove spills from my workbench. The FWW article made me wonder if other glues might not work just as well...without the staining. Any experience with other glues for bonding metal to wood?

[Pat Germain]

Thanks. Thats very interesting article. I tried the gorilla glue and didnt like it because its so messy but it does expand so it has its applications. What is the long setting glue I see mentioned on David Marks show so often for complicated glue-ups? The gorrilla glues says it sets up in 1/2 hour.

I read about this on David Marks' web page recently. He uses Weldwood, Cascamite and Urac 185. I think those are all slow setting, plastic resin glues. There were some others mentioned, but I think they were waterproof glues designed for boats.

[Howard Acheson]

>> Titebond 3 lists 58°F as the minimum temperature.

That's not correct. The specs on Titebond III is that it is usable down to 47 degrees. It's one of the benefits of using that product and is the lowest using temperature of any PVA adhesive.

[Howard Acheson]

I'd like to know what sort of hide glue they were using..Hot?, liquid bottled?, which gram strength and how was it applied...

The article goes into some of your questions. They tested both hot hide glue and liquid hide glue.

[Howard Acheson]

Now that I have had a chance to read the article in FWW, I think the test is basically flawed. Unless I'm missing something, no clamping pressure was applied to the joints. With the exception of epoxy and hot hide glue, all of the tested adhesives require clamping pressure to ensure full adhesive strength.

While I am not a fan of Poly Glue, it does require strong and long clamping to develope full strength. As I recall, the instructions call for 200 psi of clamping pressure for 12 hours. The reason that clamping pressure is important with Poly Glue is that large pressures forcing the joint apart result from the expansion characteristic of the curing adhesive. If tight clamping is not used, the surfaces will be forced apart and the joint will be filled with a foam rather than the adhesive. The foam has very little strength and may explain the poor adhesion results for that product.

There are a number of standard tests for adhesive strengths. I wonder if the writer researched any of those sources. Also, I wonder if he solicited any comments from the manufacturers.

I am sending a letter off the the publisher of FWW and may raise the issue on their website.

When it's all said and done, their results may be relevent but the fact that all had at least some wood failure shows that all had strength greater than the strength of the wood itself.

[CPeter James]

I am with Per on this. The Pl Premium is not for everyting, but it does hold and will fill a void. It is NOT for fine furniture, but for the "how do I gue this job" it may fill the bill. I buy it by the case and I am not a contractor.

CPeter

http://www.stickwithpl.com/Products.aspx?ID=Premium-Polyurethane-Construction-Adhesive

It will stick just about anyting to just about anyting.

[Mike Henderson]

Now that I have had a chance to read the article in FWW, I think the test is basically flawed. Unless I'm missing something, no clamping pressure was applied to the joints. With the exception of epoxy and hot hide glue, all of the tested adhesives require clamping pressure to ensure full adhesive strength.

While I am not a fan of Poly Glue, it does require strong and long clamping to develope full strength. As I recall, the instructions call for 200 psi of clamping pressure for 12 hours. The reason that clamping pressure is important with Poly Glue is that large pressures forcing the joint apart result from the expansion characteristic of the curing adhesive. If tight clamping is not used, the surfaces will be forced apart and the joint will be filled with a foam rather than the adhesive. The foam has very little strength and may explain the poor adhesion results for that product.

There are a number of standard tests for adhesive strengths. I wonder if the writer researched any of those sources. Also, I wonder if he solicited any comments from the manufacturers.

I am sending a letter off the the publisher of FWW and may raise the issue on their website.

When it's all said and done, their results may be relevent but the fact that all had at least some wood failure shows that all had strength greater than the strength of the wood itself.
I think their test was supposed to test the strength of a M&T joint where you can't clamp the wood beyond holding it into the mortise. The reason they used a bridle joint is so that when they did the actual test, the only thing holding the tenon would be the glue - no strength from the wood on the side of the mortise.

Your point about the wood failing is right on - for any test where the wood failed, the glue was more than adequate. But the wood didn't fail on all joints and glues tested - only on some of them.

Given their objective, I think the test was fair. We just have to realize that the test only applies to M&T joints.

Mike

[Mike Cutler]

End grain glue up in 2 stages: first stage: seal the end grain with epoxy. Second stage: sand and re-apply epoxy and make the glue joint.

Any one ever tried that?

According to the boat guys,and the epoxy forums. That techinique is similar to "sizing".
The epoxy can be drawn via capillary action up into the wood with heat applied. The ends are the "sized" and a susequent application of epoxy is applied.
I've done it on limited application where I wanted the ends completely sealed.

Bob Smalser wrote about it once. I think on this forum.

[Rick de Roque]

What I don't understand is if the wood fails and not the glue than how can they say there is a differance in glue strength (This is only for the glues that didn't fail but the wood did). once the wood fails then its a test of the wood strength not glue strength. They said some glues held better than others but its was the wood that failed, so it was a test on the wood. I'm missing something? Again this comment is only for the glues that tested stronger than the surounding wood.

rick

[Chris Friesen]

What I don't understand is if the wood fails and not the glue than how can they say there is a differance in glue strength?

Maybe some of the glues only bonded in places where there was near-perfect wood/wood contact, while others had more gap-filling ability and bonded more of the wood together?

In both cases the wood might fail, but there would be *more* wood to fail in the second case, thus leading to higher strength.

[Dan Racette]

I was really bummed that plastic resin glue didn't even make the list. I was hoping to get that in the comparison. I am a big fan of URAC 185, and was also impressed by Bob's discussions about repairability. I like Plain white PVA glue, though, as it does dry clear.

Anyone else perplexed by such a fine publication leaving that absent from the testing?

Dan

[Steve Sawyer]

I've used Gorilla glue for bonding non-porous stuff like aluminum and plastic. Normally I would never go near a piece of wood with that crap, but I did find one application that is working out so far.

I had some thin 1/4" lignum vitae planks that I wanted to bond to the bottom of a padauk plane blank (I was making a Krenov-style fore plane). Given the oily nature of lignum, and the fact that the PU glue is a little less brittle than PVA glue, I cleaned both surfaces w/acetone, applied a very thin coat of Gorilla glue and clamped the hell out of it.

I've been using this plane on a regular basis for several months, and so far, so good.

[Curt Harms]

My last two attempts at Gorilla Glue have messed up the project. One I finally planed down to clean wood. The other, gluing aluminum to oak, I messed up the aluminum finish and the glue still isn't off.

What (besides a gorilla) shoul I use for joining unlike materials like wood and aluminum? Epoxy?

Hi Brian-

I've used Roo Glue purchased from WoodCraft to glue aluminum T track in plywood dadoes for jigs. No screws or metal fasteners and so far nothing has come loose. No mess like Polyurethane, no mixing like Epoxy. It's like PVA but will glue melamine, metal and stone. I just looked on Woodcraft's site and didn't see Roo Glue so perhaps only the local stores carry it.

HTH

Curt

[Grant Wilkinson]

I've not seen the article yet, but can someone tell me what glue would be best to glue pressure treated 2x4 to a fibreglass boat deck? I was about to use Gorilla, but you guys have me worried now.

[Jules Dominguez]

I was really bummed that plastic resin glue didn't even make the list. I was hoping to get that in the comparison. I am a big fan of URAC 185, and was also impressed by Bob's discussions about repairability. I like Plain white PVA glue, though, as it does dry clear.

Anyone else perplexed by such a fine publication leaving that absent from the testing?

Dan

Dan, the FWW article described the woods, glues, joint fits and methods that were used, which allows the reader to consider the results of the tests "in context". It was a limited test, but IMO seemed to be fair and provide useful results for the conditions it covered.
FWW might be agreeable to expanding the testing in the future if they had enough reader feedback to support it.