thinned gorilla glue as a 'contact cement'?

[Bob Hammond]

Hello,

Is it possible to thin gorilla glue and then it use as a contact cement for gluing panels to XPS sheets? What non-polar solvent would be suitable? paint thinner, xylene, denatured alcohol, naptha?

I could imagine painting on the thinned glue to one panel, and then water moisturizing the second panel and laying it on the first.

[Bob Hammond]

After noodling around, I think that if denatured alcohol is a suitable solvent, then it might be the ideal solvent because alcohol is miscible with water. In fact, almost all denatured alcohol has a small percentage of water in it. The key would be to determine how much, if any, added water would work, and how fast the thinned glue would 'go off'.

Has anybody done this experiment?

[Rick Tyler]

Is there some reason you don't want to use contact cement? It works and it's not expensive.

If you want the very best adhesive, use 2-part marine epoxy with just a touch of thickening agent (like wood flour or cabosil). I guarantee this will not save you money, though, and, unlike contact cement, you will have to apply some pressure while it cures.

[Bob Hammond]

Many organic solvents dissolve foam, but the less volatile solvents aren't so aggressive. Also, clamping larger panels can be problematic around here, but maybe I could rig up a vacuum clamping system. Water-based adhesives such as 3M Fastbond 30NF are a bit pricey.

Generally, I avoid epoxy adhesives. Unless they are carefully mixed and carefully used and well-cured, they can trigger very unpleasant allergenic responses on the first use or any subsequent exposures.

[GPW]

Quote: “ Generally, I avoid epoxy adhesives. Unless they are carefully mixed and carefully used and well-cured, they can trigger very unpleasant allergenic responses on the first use or any subsequent exposures. “
That’s the same reason we AVOID Epoxy products .... we’ve gotten itchy rashes on our hands after using epoxy ( carefully) ... Even the fumes are BAD ... People that painted with Epoxy paints have experienced symptoms of a Heart Attack ... All documented on the model plane forums (RCGroups.com) ... those guys have been using epoxy on a small scale for many years now ... well tested and documented ...
Pretty much everybody there now is using something like Gorilla Glue , or UHU Por ( for you Europeans) , and even Hot Glue ... There are many fans of Hot glue for gluing foam ... Since the foam is the weakest material , it really doesn’t matter that much what Glue you use as long as it’a waterproof and won’t go runny under 190F degrees .

We used the Gripper for a “contact cement" to laminate foams together .... Took FOREVER to completely dry ,. but Sticks like the Devil ...

BH , in answer to your question ^ ... The plane guys routinely thin Gorilla Glue with water and common rubbing alcohol mixed ... It makes it dry (foam ) very quickly , but it does still expand a bit too . Vacuum bagging is Ideal to contain expansion, but Newton clamps work almost as well ... and as with everything else here in Foamieland.... Test on a piece of scrap material FIRST .... Then tell us eh !!!

[Bob Hammond]

GPW, thanks for the reply.

Immunologic reactions to epoxies can be mild or very severe, and once one is sensitized there is no way to know how severe the 2nd or 50th reaction may be. (i was a research prof in cardiac & vascular surgery for many years, testing medical devices and materials for implant, and so I know a little about biocompatibility of materials.)

As I thought and you confirmed, alcohol with water will work. Rubbing alcohol is typically isopropyl alcohol of 70-90% content with the balance of water. Denatured alcohol from the paint supply is about 90-95% ethanol, with small amounts of methanol to make it >deadly< poisonous, and a little water in the balance. If left open, a can of denatured alcohol will absorb water from the environment. So, if Gorilla Glue is thinned with denatured alcohol, it almost surely will 'go off', but i have no idea how long that might take.

Incidentally, as I recall, a treatment for poisoning by denatured alcohol (and brake fluid or antifreeze (ethylene glycol)) is an IV drip of ethanol for days. The scheme is to keep the liver and other tissues busy with competitive metabolization of the ethanol, while the methanol is excreted over the course of days or otherwise pharmacologically neutralized. Quite a hangover, i'd imagine.

[GPW]

BH , Lately we try to avoid actually touching anything doubtful .... long handled brushes , gloves , open air application ... Very cautious ...