Water Proof Glue

Hi
Pearl Sutton asked me to post my method for making water proof glue.
Here goes.

I dissolve Styrofoam in an organic solvent.
The two organic solvents I've had the best luck with are - gasoline (the alcohol free kind) and - acetone.
They give a little different appearance after they have dried, but, both are super strong and water proof.
It takes a lot of Styrofoam to make a small amount of glue.
It makes a thick gooey blob that is a bit like squishing silly putty in the joints.
It takes forever to dry. (I literally this morning just took the clamps off the box we built 4 days ago)
It expands while it dries.  So if my joints aren't cut exactly right it will expand to fill in tiny gaps.
I've only used it on wood and have no idea if it works on anything else.

To test it we took a pair of 2 foot 2x4's and over lapped them by 1 foot.  A week later we tested the strength of the glue.  We ended up denting the metal chair we had it on and the boards are still stuck together.

Phil: Thank you SO MUCH for posting this!
I have used a foam and solvent mix to burn designs in my artwork, as the foam makes the solvent stay in place where I want it burned. So beware This IS VERY flammable, and it sticks to things, and can be very dangerous if it is on your skin!!

I'm going to try it as an adhesive, I dumpster dive a lot of Styrofoam that I use for various things.

Have you tried limonene as a solvent?

I read somewhere it is used for recycling styrofoam, I obtained some for my own trials and it does dissolve it quickly.

Limonene is commonly used in store bought "natural" cleaners and degreasers. The 3d printing crowd use it for smoothing and glossing ABS prints. I got mine from amazon, it's commonly available from soap making supply shops.

The smell is less offensive than gasoline or acetone but it costs more.

Alley Bate wrote:Have you tried limonene as a solvent?

I read somewhere it is used for recycling styrofoam, I obtained some for my own trials and it does dissolve it quickly.

Limonene is commonly used in store bought "natural" cleaners and degreasers. The 3d printing crowd use it for smoothing and glossing ABS prints. I got mine from amazon, it's commonly available from soap making supply shops.

The smell is less offensive than gasoline or acetone but it costs more.

I have not.  But, if you do I'd like to hear how it went.
I've tried a couple oils and they didn't dissolve the Styrofoam very well at all.

Phil Swindler wrote:
I have not.  But, if you do I'd like to hear how it went.
I've tried a couple oils and they didn't dissolve the Styrofoam very well at all.

Challenge accepted!😃

Alley Bate wrote:

Challenge accepted!😃

I'd like to see pictures of how that turned out.

I dissolved 18 grams of white EPS foam packaging  into 51 grams of limonene so far. The mixture is perfectly clear but still a little thin . I'm dissolving a little more foam into it to get it to about the same viscosity as yellow carpenters glue before testing glueup.

Alley Bate wrote:I dissolved 18 grams of white EPS foam packaging  into 51 grams of limonene so far. The mixture is perfectly clear but still a little thin . I'm dissolving a little more foam into it to get it to about the same viscosity as yellow carpenters glue before testing glueup.

Cool!
Keep us posted.

Nice thread!
I am following with great interest.
Cheap waterproof glue would go far in making cardboard insulation panels.

Alley Bate wrote:Challenge accepted! :D

I dissolved 18 grams of white EPS foam packaging  into 51 grams of limonene so far. The mixture is perfectly clear but still a little thin . I'm dissolving a little more foam into it to get it to about the same viscosity as yellow carpenters glue before testing glueup.

I told my mom this is what I LOVE about permies, we don't disagree about things, we learn from each other and figure out what works, and how and why!
I'm REALLY interested in this experiment, as I am hyper-reactive to everything (serious health issues) but known to not have problems with limonene, in fact I take therapeutic grade limonene every morning.

I was inspired to look for alternative solvents for styrofoam, in particular ethylene glycol, as it is considered a good carrier for boron from both and boric acid, prime anti-pest and flame retardant chemicals.

This site:
https://www.bangslabs.com/common-solvents-and-non-solvents-polystyrene
suggests it might work,and has other potential solvents and non-solvents listed.

That link mentions Methyl salicylate... menthol! Wintergreen extract... Interesting!
I'll read it better later...

Glued 2 pairs with eps/limonene 20/51, perhaps still a little too thin. Left the squeeze out to see what it looks like cured.

2 pairs with yellow carpenters glue thats past its prime, if it chooches properly it should be stronger than the spruce fibers.

I've tried the 20 to 51 ratio twice now but both failed to have any real holding power. May be usefull as an alternative to penetrating polyurethane clearcoat rather than a glue at this viscosity.

I'll try significantly thickening the mixture for one more test but I suspect limonene is not an effective alternative to acetone or gasoline for this adhesive.

Alley Bate wrote:I've tried the 20 to 51 ratio twice now but both failed to have any real holding power. May be usefull as an alternative to penetrating polyurethane clearcoat rather than a glue at this viscosity.

I'll try significantly thickening the mixture for one more test but I suspect limonene is not an effective alternative to acetone or gasoline for this adhesive.

Gasoline and acetone are the only solvents I've had good luck with.

I had better luck with the alcohol free gas than the 10% ethanol variety.
I haven't tried anything with more alcohol.

Alley Bate: does it dry up hard? Would it make a good clearcoat?

Pearl Sutton wrote:Alley Bate: does it dry up hard? Would it make a good clearcoat?

I'll coat a few things with the thicker mixture. The thinner mixture left a very thin clear coat.

Sorry for the delay, I made some progress on another expirement that held my attention.

A week ago I sanded reglued and clamped with 40 parts styro 50 parts limonene. The pieces came apart very easily today so this is a failure as an adhesive.

As a clearcoat it is somewhat interesting in that it is very clear but it is still dentable with a fingernail.

Alley thanks for posting those results.
I now know to only use the llimonene version as a clear coat.
The acetone or gasoline versions still work as a glue if you can wait a week for it to dry.
I've never had a skin reaction while making either version.
I'm guessing you are really sensitive to solvents.

Alley Bate wrote:Sorry for the delay, I made some progress on another expirement that held my attention.

A week ago I sanded reglued and clamped with 40 parts styro 50 parts limonene. The pieces came apart very easily today so this is a failure as an adhesive.

As a clearcoat it is somewhat interesting in that it is very clear but it is still dentable with a fingernail.

I have use for that!
Maybe.
I want to try coating window screen with that stuff.
Should make for  tough greenhouse glazing.

William Bronson wrote:

Alley Bate wrote:Sorry for the delay, I made some progress on another expirement that held my attention.

A week ago I sanded reglued and clamped with 40 parts styro 50 parts limonene. The pieces came apart very easily today so this is a failure as an adhesive.

As a clearcoat it is somewhat interesting in that it is very clear but it is still dentable with a fingernail.

I have use for that!
Maybe.
I want to try coating window screen with that stuff.
Should make for  tough greenhouse glazing.

Sounds like a good experiment.
You never know till you try.
Can you let us know either way it goes?

Hello Alley! I laughed at seeing my name on your experiment! Looks like some interesting options to work with here. This is a fascinating thread, thanks for starting it Phil! I'll be using both the glue and the clearcoat I suspect. I will fairly soon have an excess of styrofoam cut scraps to abuse.

Pearl, Alley, & William

You got my mind churning - thank you.

I have a project I've been thinking about for awhile now.  
You guys made me realize how I might be able to do it.

I want to make cheap copies of some manufactured plastic parts.
I can use my homemade rubber to cast molds.
Then make a wad of the styrofoam/gasoline goo to fill the mold.
It expands as it dries so it should press itself into the details of the mold.
After a couple weeks of drying I should be able to pry the part out of the mold.
This will take some testing and experimentation to see how well it reproduces the part.
The strength of the finished part is another question to be answered.
Thanks for giving me something to think about.