# Why does gorilla glue recommend moistening?



## Quickstep (Apr 10, 2012)

I’m curious to know the “why” about Gorilla glue recommending moistening one surface before using Gorilla glue. 

Is it that Gorilla Glue requires moisture to cure? In that case, isn’t the 80% humidity in my basement enough to make the glue kick? Would lack of moisture just cause the glue to take longer to cure? Is a long curing time bad?

Doesn’t the wet surface impede good bonding?

I’m not necessarily questioning the practice of moistening, just interested in learning more about the chemistry behind it.


----------



## sunnybob (Sep 3, 2016)

Generally a light misting of water allows you to move the piece into final position by delaying setting.
I would think gorilla is the same.


----------



## Steve Neul (Sep 2, 2011)

Quickstep said:


> I’m curious to know the “why” about Gorilla glue recommending moistening one surface before using Gorilla glue.
> 
> Is it that Gorilla Glue requires moisture to cure? In that case, isn’t the 80% humidity in my basement enough to make the glue kick? Would lack of moisture just cause the glue to take longer to cure? Is a long curing time bad?
> 
> ...


It doesn't make a dramatic difference but it makes the surface more absorbent to wet it. It's like you can pick up more with a damp sponge than a dry one.


----------



## CharleyL (Jan 13, 2019)

Gorilla Glue is water reacting. Just like silicone caulk, it requires moisture for the reaction needed for it to set and harden. In high humidity areas it sets and hardens from the moisture in the air. In drier climates, it doesn't get enough moisture from the air to set up quickly. Adding moisture to one surface to be joined will speed up the setting and drying action of the glue. 

That being said, I have used Gorilla Glue and I don't like the foaming and the mess that it makes. I've gone back to using more traditional glues like Titebond II, III, and Titebond Extend.

Charley


----------



## woodnthings (Jan 24, 2009)

*They say it needs moisture to react ...*


----------



## Tool Agnostic (Aug 13, 2017)

I use original Gorilla glue for gluing brass insert tubes into pen blanks. I like the foaming action, which helps it fill gaps. The slight rubbery feel leaves it less brittle than ordinary CA glue. CA glue is popular for pen inserts. Some people use epoxy.

I moisten the inside of the pen blanks with a wet Q-tip before applying the glue. I have forgotten to wet the blanks a few times, and it made no real difference, although it took longer for the glue to foam and cure. We live in a pretty dry environment and I believe that the natural moisture in the wood helped the glue cure.

For regular woodworking glue joints, I use Titebond III. It is an excellent wood glue. It is waterproof and suitable for exterior use. Even though Titebond III is more expensive than Titebond I or II, it does everything I need, so with Titebond III, I don't need the other two glues.

A very knowledgeable friend just told me that Titebond II and III may not be the best for cutting boards. He shared that the water resistance / waterproofing chemical in Titebond II and III makes the glue elastomeric (more rubber-like) which is not desirable for cutting boards. He recommended Titebond I for cutting boards. It sounded plausible, anyway.


----------



## hawkeye10 (Feb 18, 2015)

I tried Gorilla glue but didn't like it because of the mess it made. (foaming).


----------



## Quickstep (Apr 10, 2012)

I completely agree on the foaming. It makes a mess and even though it will fill a gap, the foam has little if any strength.

BUT....

I’ve recently discovered Gorilla Glue Clear. It doesn’t foam and it’s dead clear. I think this stuff might be ideal for gluing pen tubes to blanks.


----------



## Tony B (Jul 30, 2008)

Some chemicals need a certain amount of moisture to hasten the curing process. That moisture may even be water. 
I am not familiar with Gorilla glue but fairly experienced with CA glue (AKA super glue. 

if you get some on your fingers it will just cure out with much notice as to time frame. If you use an Activator, the CA Glue will set up almost immediately. I dont know what is in the activator but most often, the chemical reaction is so fast and furious that it will actually smoke. Now imagine you have a fairly decent cut from a razor on your hand. Not life threatening, but something that a normal person would go and get it stitched immediately. The not so normal person, myself included, would just squirt some CA into the wound and close it up with his other hand. THEN, the quick reaction of moisture - your blood- reacts immediately. The result is SMOKING!. I mean REALLY HOT smoking. It will bring a tear to a grown mans eyes. But.........the wound is closed and within a few hours, you will be able to use the wounded hand without too much pain. I have a few of these scars which are no more visible than if it were stitched. 

Just trying to add a little more insight to the topic.


----------



## DesertRatTom (Aug 14, 2012)

I stopped using Gorilla glue because of the foaming. Nasty stuff. Question, does the clear verision foam?


----------



## Quickstep (Apr 10, 2012)

DesertRatTom said:


> I stopped using Gorilla glue because of the foaming. Nasty stuff. Question, does the clear verision foam?


No, the clear doesn’t foam. It’s viscosity is similar to Epoxy. It seems more flexible than Epoxy. It seems good for bonding dissimilar materials. I’m using it to bond glass to wood.


----------



## Tool Agnostic (Aug 13, 2017)

I have been trying out different glues for the brass inserts in pen kits. As I said above, I use Original Gorilla Glue for most pens. Last week I tried White Gorilla Glue and Clear Gorilla Glue for brass tubes in pen inserts. 

White Gorilla Glue is a polyurethane glue that foams and dries white. From my testing, I found that White Gorilla Glue was runny when compared with Original Gorilla Glue. That runny-ness caused the glue to drip from the brass tube before I could get it inserted in the blank. The regular Gorilla glue is thicker and gummier and doesn't drip. As advertised, the White Gorilla Glue cured faster than Original Gorilla Glue. It dried white, which I like. I may switch to it for pens because of the faster cure and white color, but I don't like the drippiness when applying it.

Clear Gorilla Glue is a silane-based glue. It is unlike other glues on the market. At the recommendation of a friend, I tried it on one special, challenging pen blank. It goes on clear and dries very clear. It does not foam. When dry, it has more of a rubbery feel than a "hard surface" feel. Storage is annoying: keep it cool, but keep it exposed to light.

White Gorilla Glue was the hardest to find on a local store shelf, but my local Walmart carries small bottles of Original Gorilla Glue, White Gorilla Glue and also Clear Gorilla Glue (a silane-based glue). They were the only local store I found that sells all three products. 

Pay attention to the package labels: Gorilla also makes Gorilla Wood Glue, which is white, and several types of Gorilla Super Glue, which are clear. Do not confuse them with White Gorilla Glue and Clear Gorilla Glue.

P.S. 
I want to add that these small bottles of Gorilla glues are very expensive at $6 for 2 oz. They are "cheap" for me, because I use very small amounts for pen making. A 2 oz bottle will easily glue 75 - 100 pens, but it would not be cost effective for a panel glue-up. I buy the smallest bottles I can find because they have a relatively short shelf life.


----------



## Quickstep (Apr 10, 2012)

Tool Agnostic said:


> Clear Gorilla Glue is a silane-based glue.


I've never heard of that one. Can you expand on that a bit?


----------



## Tool Agnostic (Aug 13, 2017)

Tool Agnostic said:


> [...] Clear Gorilla Glue is a silane-based glue. [...]





Quickstep said:


> I've never heard of that one. Can you expand on that a bit?


I had not heard of it until a friend recommended Clear Gorilla Glue for a special, challenging pen blank that I am working on. Before I bought the Clear Gorilla Glue, I did some internet research, and came up dry. I quickly figured out that Clear Gorilla Glue is different than other glues, but it was not easy to find the type of adhesive it is. Gorilla's website does not really explain it. The Manufacturer Safety Data Sheet (MSDS) was no help. I called Gorilla customer service and asked. Gorilla's customer support person mentioned silane, which was the clue I needed. 

I am not a chemist. I tried to pay attention in chemistry class, but it was a long time ago. There isn't much on the web that I can understand about silane-based adhesives. Here is the best description that I found:

http://www.adhesiveandglue.com/modified-silane.html

Functionally, the cured silane-based glue has a rubbery texture that is similar to the original Gorilla polyurethane glue I have been using. I like the rubberiness (elastomeric) properties because it might absorb the shock better if a pen is dropped on a hard surface. That is why I prefer polyurethane (and now silane-based) glues for brass pen inserts, compared with CA and typical epoxy glues, which are more brittle when cured.

Sorry I don't know more. I hope this helps.


----------



## Quickstep (Apr 10, 2012)

Thanks for that Tool Agnostic, that's valuable information. I kind of stumbled on Gorilla Glue Clear. Time will tell, but for what I know now, its flexible nature combined with not expanding, seems to make it ideal for bonding dissimilar materials. 

I'm curious about the "store in a cool place with exposure to light" storage instructions. Maybe it could be kept in the fridge since we really don't have scientific proof that the light really goes off when you close the door.


----------



## Tool Agnostic (Aug 13, 2017)

Quickstep said:


> Thanks for that Tool Agnostic, that's valuable information. I kind of stumbled on Gorilla Glue Clear. Time will tell, but for what I know now, its flexible nature combined with not expanding, seems to make it ideal for bonding dissimilar materials.
> 
> I'm curious about the "store in a cool place with exposure to light" storage instructions. Maybe it could be kept in the fridge since we really don't have scientific proof that the light really goes off when you close the door.


You're welcome. I see Clear Gorilla Glue as an excellent one-component replacement for two-component clear epoxy glues when used as adhesive, not as a structural filler. 

Clear Gorilla Glue yellows over time in the dark. It needs the light to stay clear. I don't remember where I learned it, but I think it was the phone conversation with the Gorilla customer support person.


----------



## Packard (Jul 27, 2018)

The term I read was "cross link". The article said that the Gorilla glue continues to cross-link and continues to improve in strength. The water is supposed to accelerate that process.


----------



## Tool Agnostic (Aug 13, 2017)

I just found the perfect use for Clear Gorilla Glue. I used it to glue two short wood pegs to that fibrous backing on hardboard. The hardboard is only 1/8 inch thick, so it is too thin for screws. I wasn't sure that the glue would hold, but it worked perfectly.

Background information you can safely ignore: 

I made a small hardboard pad with two pegs that line up with the dog holes in a workbench vise. The workbench usually has a hardboard cover to protect it. The vise was 1/8 inch lower than the top, so I made a hardboard cover for the vise that stays in place with the two pegs. It may be "vise abuse", but sometimes I open the vise to drill through the gap with a handheld drill. Now it is easy to match levels when the workpiece rests on the vise.


----------



## epicfail48 (Mar 27, 2014)

Short answer, the polyurethane used for the adhesive requires moisture to kick off the polymers cross-linking process. Think of it as something like a 2 part epoxy, where the 'resin' portion is the gorilla glue and the 'hardener' is the water. Since the water is required for curing, the makers of GG probably recommend dampening the surfaces to ensure the water is there. As people have attested, its possible to skip this step and still have the glue cure with just atmospheric moisture, but 'possible' and 'will' are different things, and the instructions have to have a method that works 99% of the time.

Also, the "cool, dark place" recommendation for storing the clear stuff is likely to prevent UV degradation from making it cloudy, as well as slow down unintended curing. Plastic is permeable to moisture and heat can do weird stuff to glue, and cool air is both lower in moisture and heat


----------



## Steve Neul (Sep 2, 2011)

The bottom line though is gorilla glue is a poor adhesive only good where parts don't fit so well. The foaming action fills those gaps. On well fitted parts there are much better adhesives a person could use.


----------



## IowaDave (May 21, 2015)

CharleyL said:


> Gorilla Glue is water reacting. Just like silicone caulk, it requires moisture for the reaction needed for it to set and harden. In high humidity areas it sets and hardens from the moisture in the air. In drier climates, it doesn't get enough moisture from the air to set up quickly. Adding moisture to one surface to be joined will speed up the setting and drying action of the glue.
> 
> That being said, I have used Gorilla Glue and I don't like the foaming and the mess that it makes. I've gone back to using more traditional glues like Titebond II, III, and Titebond Extend.
> 
> Charley


Has anyone else that used Gorilla glue noticed that the inevitable squeeze out that falls to the bar clamps below is much tougher to remove from the clamp action than a regular wood glue? I have some Bessey bar clamps and I have gone away from Gorilla because it is so time consuming and tedious to remove the dried residue on the bar clamps.


----------



## Tool Agnostic (Aug 13, 2017)

QUOTE=epicfail48;2061117] [...] Also, the "cool, dark place" recommendation for storing the clear stuff is likely to prevent UV degradation from making it cloudy, as well as slow down unintended curing. Plastic is permeable to moisture and heat can do weird stuff to glue, and cool air is both lower in moisture and heat[/QUOTE]
Actually the "clear stuff" (Clear Gorilla Glue) should be stored in a cool place with light exposure, not the dark. It is my understanding that the light helps keep it clear and prevent yellowing. Clear Gorilla Glue is not a polyurethane glue.


----------



## Larry42 (Jan 10, 2014)

Thanks for the link. 
I really don't like to use urethane glues, the CO2 foaming makes a mess and if you use them to take care of sloppy fits you are still getting a poor glue line. The Hot melt urethanes like 3M sells work very well for odd material fastening, cost a lot. I've never tried the Silane adhesives.


----------



## jason789 (Jun 19, 2019)

Quickstep said:


> I’m curious to know the “why” about Gorilla glue recommending moistening one surface before using Gorilla glue.
> 
> 
> 
> ...


It creates a better bond with the surface being glued.
If you look at fibre glassing , pre wetting the surface is a known factor in creating a stronger bond when laying fibre glass.
Cheers, 
Jason

Sent from my SM-J710GN using Tapatalk


----------



## Onefreetexan (May 3, 2018)

jason789 said:


> It creates a better bond with the surface being glued.
> If you look at fibre glassing , pre wetting the surface is a known factor in creating a stronger bond when laying fibre glass.
> Cheers,
> Jason
> ...



Not sure about all that, being an old time fiberglass worker myself,,,but do what ever turns you on.


----------



## jason789 (Jun 19, 2019)

Onefreetexan said:


> Not sure about all that, being an old time fiberglass worker myself,,,but do what ever turns you on.


Well, if you are an old fibre glasser ...
Look at construction techniques with marine ply and fibre glass. Pre wetting is standard procedure (using resin) with both glueing/filling joints and with laminating joints and the panels themselves, even laminating layers pre wetting with resin is a standard procedure....or does that statement need some sort of correction?
Cheers,
Jason

Sent from my SM-J710GN using Tapatalk


----------



## Tool Agnostic (Aug 13, 2017)

jason789 said:


> Well, if you are an old fibre glasser ...
> Look at construction techniques with marine ply and fibre glass. Pre wetting is standard procedure (using resin) with both glueing/filling joints and with laminating joints and the panels themselves, even laminating layers pre wetting with resin is a standard procedure....or does that statement need some sort of correction?
> Cheers, Jason


You just made it. The correction you made was "pre wetting with resin", above.

(Lacking any experience with fiberglas, when I read your first statement, I assumed you meant water when you wrote "pre wetting". Your subsequent post fixed that to clarify that you meant "pre wetting with resin.")


----------



## Hawaii Chris (Feb 11, 2021)

Tony B said:


> Some chemicals need a certain amount of moisture to hasten the curing process. That moisture may even be water.
> I am not familiar with Gorilla glue but fairly experienced with CA glue (AKA super glue.
> 
> if you get some on your fingers it will just cure out with much notice as to time frame. If you use an Activator, the CA Glue will set up almost immediately. I dont know what is in the activator but most often, the chemical reaction is so fast and furious that it will actually smoke. Now imagine you have a fairly decent cut from a razor on your hand. Not life threatening, but something that a normal person would go and get it stitched immediately. The not so normal person, myself included, would just squirt some CA into the wound and close it up with his other hand. THEN, the quick reaction of moisture - your blood- reacts immediately. The result is SMOKING!. I mean REALLY HOT smoking. It will bring a tear to a grown mans eyes. But.........the wound is closed and within a few hours, you will be able to use the wounded hand without too much pain. I have a few of these scars which are no more visible than if it were stitched.
> ...


It works well to glue skin, but not because it’s wet. Well not entirely... 

The water in the blood (or anything else) will cause the cyanoacrylate to eventually de-bond. That’s why CA (cyano-acrylate) isn’t the best for underwater use. The acrylic side of things is hydrophobic.
It is however very sensitive to pH to start the reaction. As in all chain reaction, the more catalyst you add, the quicker it goes. Even to the point of smoking. In fact, those giant tankers on trains that contain industrial amounts of acrylate are absolutely bombs (traveling through our cities at all hours) If one of those were to react, it would give precious little time to bend over and kiss your butt goodbye...

So in the case of hardening in a skin cut, (or anything else you are glueing) if you add the tiniest amount of base, it’ll kick right now. So a tiny residue of baking soda for instance will almost immediately harden CA. Or, if your brave, pour a puddle of CA and drop a couple grains of draino in it and stand back. It’ll flash hard pretty quick and release a ton of heat. Or don’t...


----------



## Tool Agnostic (Aug 13, 2017)

Related: 
Do not use Gorilla Glue as a hair spray, either.


----------



## Dave McCann (Jun 21, 2020)

Tool Agnostic said:


> Related:
> Do not use Gorilla Glue as a hair spray, either.


At the risk of getting booted,,,,,,,,,, My reaction to that event was/is " define dumber than a rock!"


----------



## B Coll (Nov 2, 2019)

Quickstep said:


> I’m curious to know the “why” about Gorilla glue recommending moistening one surface before using Gorilla glue.
> 
> Is it that Gorilla Glue requires moisture to cure? In that case, isn’t the 80% humidity in my basement enough to make the glue kick? Would lack of moisture just cause the glue to take longer to cure? Is a long curing time bad?
> 
> ...


Fine Woodworking did a study of the common glues a number of years ago. You can likely find it in their archives. Most of the glues, for practical purposes, were about the same in bonding and strength. Polyurethane glue, Gorilla glue, was in a class by itself, horrible strength. The author went as far as to say polyurethane is better left for finishing. The two best rated glues were Titebond Original, and Epoxy, both having very similar strength qualities. Epoxy faired better in open joints and maple for some reason. Titebond faired better in tight joints and most other woods.


----------



## B Coll (Nov 2, 2019)

Tool Agnostic said:


> Related:
> Do not use Gorilla Glue as a hair spray, either.


She is suing Gorilla Glue and has made over $15k on a Gofundme page. pays to be stupid.


----------



## Rebelwork (Jan 15, 2012)

Wet because it says so?


----------

