[lizzyborden]

I've decided to finally build my cemetery this year and am planning on reinforcing some store-bought tombstones with additional foam. In the past I've used the Liquid Nails foamboard adhesive, but from what I remember, it really didn't go that far. I have probably 30 med/large tombstones to do and using the foamboard adhesive could get expensive fast.

I know that some people report success using Glidden Gripper as an adhesive. Anyone have any insight on how well it works? The only place I can find it is at Home Depot and that is a 50 mile drive to a town I rarely visit, but at $23 a gallon, it very well may be worth the drive. My main question is how well does it hold together? I really don't want to put several hours into a tombstone only to find it will eventually separate over time.

Also open to other options as well. I was in the process of making a tombstone a few years ago when I ran out of adhesive. I brushed Titebond II wood glue between the layers of foam and it did work. The only downfall was that it took several days to completely dry and the drips made quite a mess. I've also read about others using great stuff as an adhesive too, but thinking that too could be very messy and expensive.

 

[dpeterson]

I was wondering if anyone has tried using 3M Polystyrene Insulation 78 Spray Adhesive? I have used their Super 77 spray a lot with great success with paper and other materials, but that would eat expanded foam. 78 seems made just for what you're talking about. One can coverage seems to be 50 sq feet if spraying both surfaces, or 100 sq feet if only one surface. It also gives time to position the surfaces together for alignment (some grab instantly). Seems perfect for tombstones, but I've never had the chance to try it. Anyone?

I've used liquid nails for years, and it works, but it has crap coverage, crap application, and just doesn't seem fit for (tombstone) purpose.

 

[J-Man]

The spray adhesive does work but it's tough to control the overspray and can get messy. A can also doesn't go far. I've never used the water-based contact cement but it looks like it would work really well for foam, plus you can brush it on for better control. Price ain't bad either and you can have it shipped.
https://www.walmart.com/ip/Dap-2533...93696&wl11=online&wl12=20370898&wl13=&veh=sem

 

[Cephus404]

To be honest, white glue works fine. I tried a couple of things this year for gluing foam and finally settled on white school glue. It was cheap, I just spread it evenly over the foam and clamped it together and it never failed. Granted, I don't have the kind of weather extremes some people have, but it bonded fine for what I was doing.

 

[lizzyborden]

Hmmm... you've given me some options I didn't know about. I'd really like to stay away from spray adhesives because my toddler will likely be nearby while I'm working on these and don't want her sticky and especially not high. The Super 78 adhesive does look promising, but at $16 for a 24oz can, I'm afraid the cost would be astronomical given the amount I'm planning to do.

The contact cement looks promising. I'll have to do some research on it.

Cephus, how did the items fare after being exposed to the elements? We had a rainy October this year and wonder how the white glue would do if exposed to damp conditions. Wondering if a coat of drylok would sufficiently seal it? About how long before the glue dried? When I used the wood glue, it took over a week to dry.

 

[J-Man]

Be careful if you use white glue, there's two varieties. The regular "school" glue is washable after it dries which means it won't hold up in rain. The other problem is when using it with closed cell foam like pink or blue, it will never dry except for maybe around the edge. It will also drip just like the Titebond.

 

[Cephus404]

Be careful if you use white glue, there's two varieties. The regular "school" glue is washable after it dries which means it won't hold up in rain. The other problem is when using it with closed cell foam like pink or blue, it will never dry except for maybe around the edge. It will also drip just like the Titebond.

Since the OP specified store-bought tombstones, it probably wasn't closed cell foam, more likely styrofoam, which dries quite easily. And as I said, I have no weather to worry about, so rain isn't an issue. It hasn't rained here on Halloween in... well, I stopped looking past 25 years ago, but probably longer than that.

 

[dpeterson]

Menards has a sale for about $6 a can:

https://www.menards.com/main/paint/adhesives-tape/spray-adhesives/3m-trade-78-polystyrene-foam-spray-adhesive-17-9-oz/p-1444421720112.htm

 

[lizzyborden]

Be careful if you use white glue, there's two varieties. The regular "school" glue is washable after it dries which means it won't hold up in rain. The other problem is when using it with closed cell foam like pink or blue, it will never dry except for maybe around the edge. It will also drip just like the Titebond.

.

Wondering if the "glue-all" variety is any more waterproof?

Since the OP specified store-bought tombstones, it probably wasn't closed cell foam, more likely styrofoam, which dries quite easily. And as I said, I have no weather to worry about, so rain isn't an issue. It hasn't rained here on Halloween in... well, I stopped looking past 25 years ago, but probably longer than that.

The tombstones I'm using are indeed storebought. I'm planning to add a layer or two of foam to make them sturdier. I'll use whatever I have lying around first which will be a combination of both styrofoam and polystyrene. We occasionally have snow and usually rain before Halloween, but the wind here is horrible.

 

[lizzyborden]

Here's a link to some I did five years ago using Liquid Nails and styrofoam. They made it out two different years and are still in pretty good shape though they could use a new paint job.

http://www.halloweenforum.com/general-halloween/124260-my-dollar-tree-tombstone-modifications.html

 

[Cephus404]

The tombstones I'm using are indeed storebought. I'm planning to add a layer or two of foam to make them sturdier. I'll use whatever I have lying around first which will be a combination of both styrofoam and polystyrene. We occasionally have snow and usually rain before Halloween, but the wind here is horrible.

The wind is terrible here too but everything I glued stood up to the best Mother Nature could throw at it. I had some that I didn't glue break that had to be repaired, but in most cases, the glue is stronger than what you're gluing, so if it fails, it's the material and not the glue that does. You can also use something like Titebond II, which is specifically waterproof.

 

[Bryan316]

I am now a superfan of Gorilla Glue. It foams up and expands, so it fills voids. But it'll also separate if you don't clamp or tape em together. Use a barbecue brush to scrape up the foam's surfaces, and you'll never ever get the pieces to separate. It dries ROCK HARD, so if you want to actually sculpt with it, you better have sharp tools. If you wanna experiment, brush it onto exterior surfaces to get a very textured, bumpy finish. I tried this to make bricks and rocky surfaces. Technique is YUGE for this so play around and see how it turns out once it expands and cures completely. Plus, it's hella waterproof and almost acts like armor for sensitive corners or surfaces, since it dries so hard.

I'll use the PL300 blue glue for some stuff, but lately, it's been all Gorilla Glue. It's so damn permanent!

 

[lizzyborden]

I am now a superfan of Gorilla Glue. It foams up and expands, so it fills voids. But it'll also separate if you don't clamp or tape em together. Use a barbecue brush to scrape up the foam's surfaces, and you'll never ever get the pieces to separate. It dries ROCK HARD, so if you want to actually sculpt with it, you better have sharp tools. If you wanna experiment, brush it onto exterior surfaces to get a very textured, bumpy finish. I tried this to make bricks and rocky surfaces. Technique is YUGE for this so play around and see how it turns out once it expands and cures completely. Plus, it's hella waterproof and almost acts like armor for sensitive corners or surfaces, since it dries so hard.

I'll use the PL300 blue glue for some stuff, but lately, it's been all Gorilla Glue. It's so damn permanent!

Wow! Never really thought about Gorilla Glue though I found out how it foams as it dries by accident several years ago. Also never though about using it on the exterior of the foam--that would create quite a rigid barrier. I'll give it a try on sandwiching the foam layers.

 

[eightcircuits]

I have never had a problem with Liquid Nails. Are you using the blue can? it has less of a peanut butter consistency and more of a glue.

 

[lizzyborden]

I have never had a problem with Liquid Nails. Are you using the blue can? it has less of a peanut butter consistency and more of a glue.

Yes, that is what I've used in the past and those tombstones are still holding up pretty well. I did use the more common adhesive (the peanut butter stuff) on the last one I did and wasn't impressed at all.

I recently cleaned out my entry closet and found several tubes of clear silicone. So now I'm wondering how it or perhaps caulk would do as a foam adhesive?

 

[Bryan316]

I have never had a problem with Liquid Nails. Are you using the blue can? it has less of a peanut butter consistency and more of a glue.

I found that Liquid Nails eats away foam. Standard construction Liquid Nails dissolves the foam. We found this when my cemetery gates had the bases separate. The Liquid Nails was glued firmly to the wood framework, and the foam had "worm trails" where they contacted the glue. The foam collapsed away from the Nails. After research, turns out, Liquid Nails does use acetone as its solvent. PL 300 blue panel glue does not.

Of course, do some tests and see what happens with your foam.

 

[Joven76]

I'm surprised no one has mentioned Great Stuff as an adhesive. That's how I glue my foam together to make my stones. When it dries, it won't come apart and because it's foam, I can use a hot wire cutter with it, sand it, paint it, just like the foam board I'm using. Just spray some Great Stuff in between the two pieces of foam, put something heavy on it, and let it cure. Viola!

Just my 2 cents.

 

[Bryan316]

I'm surprised no one has mentioned Great Stuff as an adhesive. That's how I glue my foam together to make my stones. When it dries, it won't come apart and because it's foam, I can use a hot wire cutter with it, sand it, paint it, just like the foam board I'm using. Just spray some Great Stuff in between the two pieces of foam, put something heavy on it, and let it cure. Viola!

Just my 2 cents.

The thing about Great Stuff, is it becomes difficult when using on small details. I used a whole damn can of it inside the plinth for my Grim statue. It was easy to just let it fill everything up, cuz it was all concealed and I didn't care how much it expanded. But if I was trying to use it for my tombstones or some exterior details, I'd worry about the expanding forces that foam creates. It is just like Gorilla Glue. You gotta clamp things. So that must be accounted for as you plan your setup before you apply it.

Otherwise, it is wonderfully sticky and as permanent as the foam you're sticking it to.

 

[Castart]

This year I used a caulking gun based gorilla glue. Worked well did not notice it expanding like the regular glue.

 

[lizzyborden]

This year I used a caulking gun based gorilla glue. Worked well did not notice it expanding like the regular glue.

Hmm... haven't seen that before. Will have to check it out.