Fast drying and waterproof glue

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Justan2

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I’ve been working with gorilla glue and have found it somewhat unpredictable. Gorilla glue uses water as a catalyst and water makes the glue expand up to a lot depending on how much water is in the mix. It dries to tack in 2 hours but a couple of drops of water one way or another has a huge impact on how much it expands.

Anyone know of something which is fairly fast drying (1 to 2 hours to tack) but more predictable?
 
Gorilla glue is polyurethane; very strong, but unsuitable for wood frame miters, because the unpredictable foaming action ruins the finish.

Ordinary PVA "white glue" takes 10-15 minutes to set-up, and it dries to about 80% of ultimate strength in a couple of hours. If you are looking for a faster-drying adhesive than that, try cyanoacrylate, aka Super Glue.
 
Is pva such as corner weld glue water soluble?

Super glue is a little too fast drying for the task. i need something that has enough time to spread out a bit.
 
PVA is water soluble so a glob that may ooze out without being wiped away while wet is best removed with a bit of spit on your finger. Larger amounts can be cleaned by using a damp towel to soak a bit and then removed.
 
^What I thought. This application will be subjected to repeated contact with water and some other liquids as well.

Too bad as I’ve come to love what can be done with corner weld.
 
There are 'exterior' versions of PVA which are supposed to be weatherproof and therefore one would assume waterproof.

I ordered some by mistake once and used it. It behaved just the same as interior PVA on frames,
but I didn't stand them outside to see how waterproof it was. ;)
 
What are you gluing?
 
There are 'exterior' versions of PVA which are supposed to be weatherproof and therefore one would assume waterproof.
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Do you or anyone know of an example? I found a reference to Titebond III as an exterior pva but it turned out to be polyurethane, as is gorilla glue.

What are you gluing?
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Hard to describe but it is type of a molded plug that has to end up being a fairly specific form factor, and be waterproof.

The glue also needs to be non-toxic as I’m using it in a garage environment (read that, inadequate ventilation). If it weren’t for the non-toxic element, duco would be an excellent choice.

If I can get a workable ratio of gorilla glue and water that will work. I’m continuing to experiment….
 
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^Definitely a candidate but may be too viscous at the casting stage for my purpose.

Just got off the phone with the support guru at fiberlay and he made 3 recommendations. I may try some P16 polyester resin (aka fiberglass resin) as it doesn’t expand and the cure time varies greatly depending on the amount of catalyst used. Plus it is not overwhelmingly toxic.
 
Thank you. I found a data sheet and Evo-Stik Wood Adhesive Exterior is a PVA glue but water resistance is stated as "Good but only to occasional exposure". So close....
 
I can't remember why I stopped using this product, I think my brain is going.
 
There is also evo stick resin w that is also supposed to be weather proof
 
Titebond 2 "passes the ANSI Type II water-resistance specification."

In my experience it has slightly lower viscosity than regular PVA and dries a little quicker.
 
You can get 2-part epoxy in gel form. Good viscosity.
 
Two part epoxy will stick like the proverbial, but it's a pain to work with.

There are different formulations. The 'quick setting' type sets too quick. You nearly have to mix a batch for each corner. 5 minutes and it's unworkable.
The longer curing types give you more time, but they need overnight to cure to full strength and like PU they tend to expand as they cure so the joint must be held very tight.
You have to watch oozes on the face of the moulding. Cleaning it off while 'wet' is tricky. If it sets it will be next to impossible to get off without marring the finish.

Both are very messy. And very expensive.


Actually, if the joints are going to be subject to extreme wetness I would be more concerned with the wood swelling and breaking the joints rather than the glue integrity.

I've just had a lean out the window to look at the joints on my sign which has a 1" frame around it. They look OK. It's been hanging in the sun and rain for 21 years.
It was plain wood with about 10 coats of exterior varnish on it. As far as I can remember, it was glued up with 'cooking' grade PVA.
 
Speaking of the proverbial....

31t8SPaSyXL._SY300_.jpg


Never tried it.
 
Scallywag said:
I think you should try Titebond III. It shouldn't expand like Gorilla Glue does.
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Thanks that will my next glue to try. Gorilla Glue has a lot of seductive qualities but it is not controllable for my application. I did 12 carefully controlled experiments and got 2 positive results.

If I could make a 2 part mold with a collar to put a cap on how it spreads, that would probably do the job. Probably being the operative word. Even with 2 drops of the stuff with 1 drop of water it is hard to predict how much it expands.


I'll track down some Titebond III today.
 
You mention you are making some sort of a cast plug so have you considered just making it out of Bondo. You can make a mold for it from dental impression putty and then it would just bend away and pop out ready for the next one to be cast.
 
^I haven’t used Bondo for a number of decades but way back when, Bondo was a paste and I need a fairly low viscosity liquid. Part of what the plug does is to hold a bunch of fibers in place and the glue needs to spread itself into the fibers pretty well.

I already made a mold out of silicon rtv which will let me produce up to 70 of these at a time.

If Titebond III doesn't work, my next evaluation candidate will be P16 polyester resin or perhaps an acrylic. Problem with acrylic is the fumes and that the pot life is usually pretty short but i'm told the pot life can be fairly controllable with some acrylics.
 
try Liquidtex gloss poylmer medium or varnish it stcks well and as far as out door they used it to coat the Goodyear blimps
 
Bondo starts out the same consistency as wood glues like Corner Weld, Maxim, etc. The more hardener you use the faster it sets up so unless these are quart size pieces you would have no problem getting the right mix of Bondo and hardener. You may need to do fewer at a time but the set up time can be very short so you would speed up the overall process even though you would be mixing multiple batches.

The stuff also costs less than $15 per gallon vs. about $50 for good PVA glues. Stop into Wal-Mart who carries several brands of the body filler and sells the $4 size in each brand so you can test the different ones out.
 
Thank you Gumby and Jeff,

I have some spar urethane on hand and may try that.

Bondo is not at all as i remember it and sounds like a good cantidate.

Interesting article on polyurethane...

http://www.christinedemerchant.com/adhesive-glue-polyurethane.html

For completeness, I'll try another test with gorilla glue where I don’t add any water. There may be enough humidity in the air to permit it to cure with minimal foaming.

According to the details on the bottle, Tightbond iii is not suitable for prolonged exposure to water. After 8 hours a roughly ½” x ½” volume of Tightbond iii has not even started to cure. This combination makes it unsuitable for my application. Bummah!

Because I have some on hand, I’ll try some 2 part polyurethane intended for casting. It has only a 3 minute pot life but I understand that can extend that by using a little less of the activator.
 
Be warned that "regular" Bondo is not waterproof. However, there are some varieties available that are.
 
^Thanks i read about that.

Re Tightbond III, after 32 hours in the mold it has only barely begin to set but still liquid. I pulled the tests and cleaned out the mold. Duco glue is next and this weekend i'll test with some casting urethane. I predict one of these will get me to the 2nd and 3rd tests of long term water immersion and also solvent resistance.
 
Two successful tests!

I did tests with Duco and LockTite Plumbing and Marine Adhesive! Duco appeared to be absorbed into the fibers better but did not make a plug shape in the mold as desired. I may not have used enough. Locktite made a nice plug shape. Both stabilized the fibers well. I demolded both after about 8 hours and they are stable but soft. They take about 24 hours to fully cure.

The fumes are obnoxious but i may have to adapt to that.

Will repeat the tests and then test for stability in water immersion for a few days and also for stability against solvent submersion.

Still plan to test some casting urethane this weekend, cus it is the fastest acting and may be the most resistant to water and solvents. But anyway, i'm happy to see this project appear to inch forward.
 
So the victor in my little research project turned out to be SharkThane Hard Pro 70-3 made by Fiberlay. Here is a link to a data sheet for anyone interested. This is a casting urethane, and I’ve used it for a variety of other projects. http://www.fiberlay.com/upload/techd-300403700310-SharkThane Hard Pro 70-3 tds.pdf

It made from a 2 part mix with a so-called pot time of about 3 minutes and a demould time of about 30 minutes. It fully cures overnight. I’ve made about 100 castings so far and the finish quality is coming along nicely as i learn how to stuff the fibers into the wet casting material. Because the stuff starts to solidify pretty quickly I can only make about 20 small castings at a time. I’m doing the work outside due to the fumes and wear a high grade particle mask and glasses. The best part for now is with the outside temp in the mid 50 degree range the pot life is a little longer and so is the drying time.

There is a variant of this with a pot time of 20 minutes. I will switch to that once I run out of the current supply. It will be great to have more time so i can apply a precise amount for each mold.
 
Justan2 said:
I’ve made about 100 castings so far and the finish quality is coming along nicely as i learn how to stuff the fibers into the wet casting material.
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I think I'm not the only one who would be interested in just what this is that you're making. Pics and description?

Justan2 said:
I’m doing the work outside due to the fumes and wear a high grade particle mask and glasses.
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Glasses are important, but that mask is really not doing anything. You should really be wearing a respirator with a filter specific to the material. Your SDS will tell you what you need.
 
^Thank you David.

I will post some information when I have the product line ready. That will be hopefully in about 1.5 months as I have my first show at about that time.

The mask I use is named a “N95 respirator” which is designed to block “at least 95% of all particles down to .03 micron in size” according to the specifications. It was recommended by the folks at Fiberlay. It’s not perfect but given the environment I work in (the deck behind my house, that is) and small volume of toxins I use, it’s almost the same capability as my full face respirator and a lot more comfortable.

I also wear Nitrile gloves when working with nearly anything from cat litter to….
 
Justan2 said:
The mask I use is named a “N95 respirator” which is designed to block “at least 95% of all particles down to .03 micron in size” according to the specifications.
Click to expand...

That is a Particulate Respirator only, and will not prevent any gases/VOCs from passing through. For VOCs you need a Chemical Respirator, such as an activated carbon one typically used in a paint spray application.

Using a relatively small amount of this product, in a well-ventilated area, you are probably at very low risk. But really - don't think an N95 is doing anything.
 
^I checked with the product specification and they state: “In the absence of good ventilation, use respirator equipped with organic vapor cartridges and HEPA filters.”


While the ventilation is pretty good, you are correct and I’ll switch to using one of my respirators.
 
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