# Foam-styrene adhesive pull test



## CliffyJ (Apr 29, 2009)

Here's a little test I did today, to try to see what adhesive works best between styrene strips and bare foam board (XPS, or extruded polystyrene). 

Candidate adhesives were these:










The setup was pretty simple, just a wire hook and a way to suspend it, a scale, and some objects for weight.









Basically I started adding weight to the middle of the board (between the hook and the other end). The pounds it would take to pull the strip free (divided by 2, because the weight was shared by the other end of the board) would give some indication of relative joint strength.









When it broke...









...I weighed what it took. Sometimes it took a lot.









I did this for 3 strips, with each of the 3 sample boards. Here are the results.








[Morning after edit: I saw that my spreadsheet had an equation error in the total lbs column, skewing the results a bit. So I replaced this figure. No change in the "winners," but sorry about that!]

This isn't the most scientific test, so take it with a grain of salt. Anyway, I've got all the sample boards weighted down in a bucket of water for about 24 hours, and will try to see if there's any degradation in the bond.

===>Cliffy


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## Ray Dunakin (Jan 6, 2008)

Interesting!


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## Mike Reilley (Jan 2, 2008)

Did ya let the glue set up for over 24 hours? Great test Cliffy?


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## CliffyJ (Apr 29, 2009)

Thanks guys!
Yep Mike, those sample boards had 4 days to cure.


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## SD90WLMT (Feb 16, 2010)

Great minds....

Dirk


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## MikeMcL (Apr 25, 2013)

I've used both 100% silicone and Liquid nails, but I didn't get all technical about it, LOL! I can tell you that Ace Hardware version of liquid nails was not as good as the real thing, and Ace version attacked the foam more. 

I'd be interested in pull tests (or are you really doing a peel test?) using Silicone!


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## CliffyJ (Apr 29, 2009)

Good point Mike. I have the silicone, so I might do that.


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## CliffyJ (Apr 29, 2009)

After 50 hours underwater, I pulled the test boards out for for more pull-testing.

Mainly I just wanted to see if there was any dramatic change in the bond, and there wasn't. These are the "Avg Lb / 2," that is, the approximate pounds it took to tear the styrene strip up.

Loctite PL3X: 11.37
Loc. PowerGrab 10.73
Liquid Nails HD 9.17

I'd put a square blob of each material on the upper right corner of their board. None were hard anymore, and the PowerGrab was particularly squishy. It still performed well though, surprisingly.

Funny, the PL3X did better after the soaking. But that's just probably a random artifact.

The LN HD's blob was the firmest. And though it didn't perform quite as well as the Loctite PG, maybe it did well enough. it's a lot less expensive (per an online check at Amazon):

Loctite PL3X: $7.92
Loc. PowerGrab $10.41
Liquid Nails HD $3.46

So, take it for what it's worth. 

===>Cliffy


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## SD90WLMT (Feb 16, 2010)

So ..Cliffy...!

Can you please comment on the viscosity for these bonders. .

Have only used L.N. for normal construction projects. ..and I find it very.." thick " 

Not sure I want something that heavy bodied for models..

So what are the others like..?

:-D

Thanks Buddy!!

D


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## CliffyJ (Apr 29, 2009)

I agree, the LN is very thick & sticky. The PL3X is similar. 
Powergrab is like thick mashed potatoes, and isn't as sticky as the others. 
Zat help?


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## SD90WLMT (Feb 16, 2010)

Can you do a test using Titebond3....

Is this suitable for your intended uses?

D


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## CliffyJ (Apr 29, 2009)

I've not heard that TB 3 will work on styrene... have you?


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## SD90WLMT (Feb 16, 2010)

There we go..it may not "bite" the plastic..

How 'bout ...Red Hot Blue glue..

same as I use for my ladder system...

D


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## Totalwrecker (Feb 26, 2009)

When are you going to do the other half of the test?
How long before they dry out / bake to the point of failing?

Out here where the sun is hot, I've had glued construction fail where a mechanical one didn't.....

John


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## placitassteam (Jan 2, 2008)

I use Titebond III on the pink foam board and find that as long as the joint is tight it works very well. On a building that has been outside for 5 years the only failure has been where I glued wood siding to the foam. In that case the failure was due to the wood warping and actually pulled off the surface of the foam! The glue did not fail but the foam did.


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## CliffyJ (Apr 29, 2009)

Thanks for all the good thoughts guys.

That's a great data point Winn. In all my (brief) tests, the glue pulled away from the foam, leaving it intact. I'd like it to bite much better than that.

I read yesterday that an epoxy-based adhesive, and also Lapage's contact cement, wouldn't attack the foam and would work well. And Gorilla Glue was supposed to be good. Maybe TB3 is of the same sort.


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## Mike Reilley (Jan 2, 2008)

WOW!!!! Titebond III on foam...and it's the FOAM that fails? Where as all of Cliffy's construction glues...the GLUE JOINT failed. That's a HUGE difference in strength.


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## CliffyJ (Apr 29, 2009)

I agree Mike. I was concerned that the foam didn't fail in any of my tests. Didn't even try to tear, except for some slight greenish hue on the glue. 

So... I've got the TB3 & silicone already, and will pick up some Gorilla Glue and Lapage's water-based contact cement (both claimed to be good stuff on EPS) on the way home from work today, and run all those through the mill.

[edit, a few hours later...]

Well, I set up sample boards for TB3, 100%RTV, Gorilla, and a garden-variety Loctite 2-part epoxy. Couldn't find the water-based contact cement locally (and the regular stuff did melt the foam -- had to check!). 

So next weekend I'll do some more pulling. I wanna see foam chunks flying!

===>Cliffy


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## Mike Reilley (Jan 2, 2008)

I just spent 30 minutes talking to my adhesives expert. He's been building model airplanes for 50 years or so...and his main point has to do with the type of connection you are trying to make.

If you are sheathing something onto foam, the amount of air that gets to the glue becomes significant. TB3 requires air to cure...so if you use it to glue plastic to foam, it's gonna take a very long time to cure....months. He said that for glue joints that are between two air proof materials, like styrene over foam, and you want to be able to apply the styrene and adjust it for a few minutes to line it up, you want a glue that chemically cures...like epoxy. He said if you don't need to have the few minutes to line up the material, then water based contact cement is your best method...but once you set it...it ain't moving. 

He said if you are doing joints between foam sheets, then TB3 will work well IF YOU REINFORCE THE JOINT mechanically...because it takes weeks for it to dry if used on foam. So, the glue/screw method will work good for building sides. Epoxy will work well too.

He said the true test of an adhesive is how the joint fails....as you are finding. Good glue joints rip the base material. Poor glue joints separate at the glue/base intersection....so your tests with the caulking gun stuff isn't looking good. 

Lastly, he said that when you bond smooth materials to rough material (like foam cut with a saw), he recommended mixing micro balloons into the epoxy...as the micro balloons fill in the rough texture from the saw cut and cause a much stronger bond. You plop the glue/micro-balloons on the foam and spread it with a piece of plastic like a credit card....then place the other material on that. 

Thought I'd pass this on...as there were good techniques involved if you're using foam.


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## CliffyJ (Apr 29, 2009)

[dang, my reply got lost... have to come up with a quick one now...]

That's great info Mike -- especially on the foam. Thanks for all those tips, and thanks to your friend.


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## SD90WLMT (Feb 16, 2010)

Cliffy..did the wind 'blow away" your reply...
Sumth'ns brewing...n coming my way...
Supposed to get windy tomorrow...here already tho....

Doing a great job...keep trying different stuff!! This is fun!!

D


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## Naptowneng (Jun 14, 2010)

What Mike Said (From his experienced friend)

Jerry


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## Totalwrecker (Feb 26, 2009)

Cliffy, 
When you add the TBIII, also try Gorilla's Super Glue Gel. IIRC it has rubber in it....
Construction glues don't seem to be model friendly, meaning to me, hard to use on a small scale.
Thanks, by the way, thanks too for adding to the forum, you've thrown out some interesting ideas.
John


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## CliffyJ (Apr 29, 2009)

Thanks John, I appreciate that.


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## SD90WLMT (Feb 16, 2010)

John..ya have to keep yer " eye" on Cliffy now...
Hes from CA...
N he gets his ideaers from me!!!!

Dirk






I'm leaving real fast...
...a for the storm comes thru here! !!!



L o L


Boy that was fun!!!!!!!!!




D - ;-)


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## SD90WLMT (Feb 16, 2010)

Yep ..yer doing real good by us Cliffy!!!
..or maybe....mmmm
.
...we're doing real good by your ideaers....

Too much fun...

D


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## SD90WLMT (Feb 16, 2010)

Don't take it personal...
I'm jus kill'n time waiting...
...on me girl to show ..from her conf er ence....yea!!

D


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## CliffyJ (Apr 29, 2009)

Yep, you sure did ask for the TB3 Dirk. So we'll see how it stacks up against the others in today's exciting pull test!


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## CliffyJ (Apr 29, 2009)

Just concluded today's bake-off, and here are (or were) the contestants. 









Looks messy, but the scrap styrene strips were clean on the bonded side.

Here's an example of a sample that's just let go. Notice how close the bricks are. The heavier the load, the more the foam bent; so to keep things consistent, I had to keep shifting the bricks closer, so that (about) half the load was on the hook and half was supported by the table. 









After the strip broke away, I weighed what it took. And here's the record-holder load:









Can you guess which adhesive it was? 

(I was tempted to cut of the post here, but...) 

Well, here's the results.









And a summary.









Well, I think there's a clear winner. As long as the styrene can be clamped or weighted down onto the foam somehow, Gorrilla Glue is way ahead. But if not, the other products tend to work about as well as each other -- except the silicone, it tended to come off both the foam and the styrene. I'm doing these tests because I'm wanting to hold onto styrene, and a lot of it. I'm sure the results would be different for other materials. And since price of the adhesive comes in to play, I'm relieved that the epoxy didn't win!

I didn't soak these new samples. Maybe should have, but didn't. My reasoning was that since there wasn't much / any degradation between dray and after-soaking samples, my concern isn't very high.) 

A couple of notes for someone who'd like to either improve on this, or test other materials. Because like I said before, this isn't very scientific. I'd bought a digital vertical luggage scale, but it kept going into "hold" mode before I could build up the load. So that's why I ended up with this setup. Anyway, a better scale (just pulling upward), and clamps holding the foam to the table on both sides of the puller, would be better.


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## Totalwrecker (Feb 26, 2009)

For What it's Worth... I have heard concerns about Gorilla and moisture. It does require a damp surface to cure ... the worry I heard was moisture could effect the reverse. I have no further knowledge...

My suggestion was the Gorilla Super Gel glue. It's a different formula, you shake it and tap it into the spout before use... IIRC, The long tossed wrapper touted rubber as a better ingredient... 

John


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## Naptowneng (Jun 14, 2010)

Cliff- You can claim this is just a quick non scientific test, but all tests may be scientific, just with varying levels of effort and expediency

When you are ready to play with the big boys, take a gander at this

http://www.astm.org/Standards/adhesive-standards.html

have fun my friend 

Jerry


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## tmejia (Jan 2, 2008)

Thanks Cliff,

I filed your tests for future reference 

Tommy
Rio Gracie


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## Mike Reilley (Jan 2, 2008)

Good test Cliffy...and ya found a good use for encyclopedias too!!!!


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## CliffyJ (Apr 29, 2009)

Totalwrecker said:


> For What it's Worth... I have heard concerns about Gorilla and moisture. It does require a damp surface to cure ... the worry I heard was moisture could effect the reverse. I have no further knowledge...
> 
> My suggestion was the Gorilla Super Gel glue. It's a different formula, you shake it and tap it into the spout before use... IIRC, The long tossed wrapper touted rubber as a better ingredient...
> 
> John


I was vaguely concerned along the same lines. I mean, how many other glues require dampening the surfaces? And why, if the surfaces are impermeable plastic? Dunno. Anyway, you convinced me John, so put the GG sample in a tub of water with a brick. So we'll see how it does after a few days of that. 

As for the GG super glue, I totally believe that it would do the job. But, like the epoxy, I'm concerned over cost (for just this sheathing application, because there's so much surface area). So I'm really wanting to stick with an adhesive that comes in bulk, and is fairly cheap by the fl oz. But I'll buy some, to see how it does with smaller parts (vs. Loctite or some other super glue). 

Thanks,
C


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## CliffyJ (Apr 29, 2009)

Thanks for watching guys. Tommie, I hope there's something useful when all is said and done!

Jerry, those ASTM specs are too expensive for me... and I don't want to be one of the big boys on this, just wanna be sure I don't wind up with a nice foam model having a pile of styrene sticks laying around it, ha ha! But thanks for the encouragement. 

And Mike, glad you noticed, that was the first time I handled them in a couple decades... and I was thinking about that salesman almost 30 years ago, who said I'd use them all my life... guess he didn't anticipate the Internet! But, the kids have used them for school projects though. 

Anyway, they're pretty good for weight stacks!

===>Cliffy


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## CliffyJ (Apr 29, 2009)

This is the follow-up to the wrap-up. John had raised the point of water degradation of the Gorilla Glue, and I had to confess I had some doubts as well. So I put the sample board under water, and it's sat there for over 6 days.









I pulled it out, and there was no gooiness at all, really rigid where it originally leaked out.









I rigged the setup again, ran 3 strips through the test, and the average breaking load was 18.2 lbs (down from 23.5 lbs dry). Still pretty good, and better (and way cheaper) than the next contestant that I tested (epoxy). 

So thanks for raising the concern John, I feel better about using this product now.

===>Cliffy


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## jimtyp (Jan 2, 2008)

Cliffy, any interest in testing E-6000? I glued a wood bridge using Gorilla glue and another with E-6000. The Gorilla glue one failed after being outside for 2 years, the E-6000 is still holding after 5. I realize your testing is for foam, but do you think that E-6000 would work on foam?

-Jim


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## CliffyJ (Apr 29, 2009)

Good data point Jim. I've not used E-6000, but my wife has used it on craft projects. Though my main concern here is with large surface area coverage, I can see that using something super-duper on joints is important.

I see that a 2-oz tube can be had for $3 on Amazon, so it's not really expensive for a small tube of something... But, there's a 10.4oz gun tube for $8.45 + S&H. Home Depot as 12-packs for $85... 

So, maybe I'll give it a test shot. I still haven't seen anything that would rip the foam off (without resorting to a CA product).

Thanks,
Cliff


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## Naptowneng (Jun 14, 2010)

FWIW Michaels craft store carries tubes of E-6000 and has a 40% off cupon just about every week, 50% now and then

Jerry


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## Ray Dunakin (Jan 6, 2008)

Urethane glues such as Gorilla Glue recommend dampening the surface because they react with moisture as part of the curing process. In the open, humidity in the air is enough, but between two surfaces it helps to provide some moisture. However, once cured, the process is not reversible, so as you've seen, soaking doesn't affect the bond.


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## CliffyJ (Apr 29, 2009)

Thanks for the tip Jerry, I'll keep an eye peeled. 
Great confirmation Ray. And congrats / great job on your RC rail bus article!


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## Ray Dunakin (Jan 6, 2008)

Thanks Cliff!


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