Teardrops n Tiny Travel Trailers

When I first started to build a fomie Gorilla Glue and Great Stuff seemed to be the glue of choice. The main problem I had with them is that they both foam up and create a hydraulic action. It does fill voids nice, but sometimes it pushes parts apart, or lifts things I did not want lifted. In some cases I found that Great Stuff seems to deteriorate and I questioned its long term bonding ability.

In a quest to find something a bit better, I turned to Dap Alex Plus. My test sample is still kicking around in the shop, and from time to time I still try to pull it apart and it still stays as one piece (More on that later).

At a point in my build I was looking for a adhesive glue to attach my vent to the roof. I found Gorilla Glue Construction Adhesive. I gave it a try and it seemed to work good. It also worked on a few other items I tried it on and I liked it a lot. Problem is it is a bit expensive at nearly $8.00 a tube.

So I got to thinking with my #2 build what is the best adhesive for my needs. So a test was born.



The test started Tuesday with 4 products. As shown I used Loctite Power Grab, Loctite Foamboard PL 300, Gorilla Glue Construction Adhesive and Alex Plus.

I wanted to first test the bond to a piece of flashing. So I cut up some foam and used each glue/adhesive to bond a piece of foam to the flashing. The results 4 days later......

such a tease

John61CT wrote:such a tease

I know right! Got busy with other things, but now I am back.

Loctite Power Grab.

It looked promising and was a decent price at about $3.65. After 4 days it was nearly dry, just a bit was still soft to the touch. The bond to the flashing was quite good, but I found the bond to the foam to be wanting and was quite easy to pull the foam off the flashing. In fact the bond seemed to fail with the glue rather than the foam. There is very little foam bonded to the glue. I think this one performed the poorest of them all in this test.

Next was Loctite PL 300 Foamboard.

I have heard that some people have used this product in their foamie build. I though well it is for foamboard so it should be good. I was sceptical about a good adhesion to the flashing since it did not mention anything about bonding to metal. It actually seemed to bond to the flashing just fine. It also had good adhesion to the foam where it had dried around the perimeter, but past the dry PL 300 was the still quite wet PL 300. After 4 days of dry time it was still as wet as when I applied it. Separation of the foam from the flashing even with just the edges cured was pretty good and I would compare it to the Alex Plus. Both seem to be very similar with their drying around the edges and still being wet on the inside. I venture to say that like the Alex Plus the PL 300 would dry completely and create a great bond. At a price of $3.67 I think it is a better product for this application than the Power Grab, but for the price and similar observances of the curing process to Alex Plus I feel it really not worth the extra cost over the Alex Plus.

Gorilla Glue Construction Adhesive.

For this test this product is hands down the best product . Coming in at $7.97 it is also by far the most expensive and well it darn well better work good . Sometimes higher prices does not mean a better product, but in this case I assure you Gorilla Glue Construction Adhesion is worth the extra price. Just look at this picture. I had to apply a lot of force to get the foam to separate from the flashing. In fact so much force you can see the flashing has bent and the foam block is broke it two from the effort. Also, notice just how much foam was pulled off from the foam block. I have only seen this one other time with Alex Plus after a full cure of a couple weeks. This bond was after 4 days and it it was dry to the touch. It is a good possibility that it cured in a day or two. That may be a new test. I do really like using this product and after seeing this test I feel more confident in my choice. Gorilla Glue Construction Adhesive and Alex Plus is all I have used in my new build #2. I have been using the Gorilla Glue Construction Adhesive for the heavy duty gluing and Alex Plus for the light duty bonding and filling of seams.

Dap Alex Plus.

Last product for this review is Dap Alex Plus. After 4 days of cure time I found it to be nearly identical to the PL 300 mentioned above. Edges where dry and interior was still moist. Bond to the flashing was fair. Coming in a bit more economical at $2.28 than the PL 300 I would just stay with the Alex Plus for this application.

My first experiments with Alex Plus came when I found myself in search for a glue that did not expand. I glued two pieces of foam together and waited 4-5 days and then tried to separate them. I could not get them separated so I cut the block of foam in two. Once the foam was cut I tried to separate them again and had success, only because I had cut the block in two. I was able to get the foam apart from the fresh cut edge because the Alex Plus was not fully cured in the center. Once I got it apart I could see that the Alex Plus had dried around the edges about a 1/2" in, but was still soft in the center. Not knowing if it could reach a full cure once sealed I decided to let the other half of the block cure for a couple of weeks. I could not get it to separate at that point so I cut the block in two again. It appeared that at that point the Alex Plus had reached a full cure all the way through and the blocks were now a solid piece. One of those blocks is still kicking around in the shop and from time to time I still try to separate them by hand. No success as of yet.

Awesome, thanks for presenting that... good timing as I'm trying to decide what glue to use for assembly, too. :-) can I ask how many tubes of the gorilla glue construction adhesive you've needed for your #2?


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So I guess I will have to do the foam on foam test nest. I bet I already know which one is going to win...

For foam to foam, can you include Glidden Gripper?

amandacreiglow wrote:Awesome, thanks for presenting that... good timing as I'm trying to decide what glue to use for assembly, too. :-) can I ask how many tubes of the gorilla glue construction adhesive you've needed for your #2?

I am done with gluing everything and I used 3 tubes of Gorilla Glue Construction Adhesive and 3 tubes of Alex Plus. I ran two beads along each wall/floor/roof edges and once dried I calked the seams/voids with Alex Plus.

John61CT wrote:For foam to foam, can you include Glidden Gripper?

What type of bonding? Large panels or end pieces?

In my experience of using Glidden Gripper it worked pretty good for large flat areas that you are trying to laminate together as long as you got the parts together quickly. The parts have to be flat and no bends or voids. As far as end to end gluing it is lacking and I would not recommend it for that.

Very informative and useful post. Not to hijack your thread just my experience. On the foamie I built last year I ripped vinyl fence posts down making 2 lengths of vinyl angle from each and used for door frame and outside trim. I glued them in with PL 300. The trailer is used a s a hunting blind and has sat in the woods since last October. Still dry and looking good

greygoos wrote:Very informative and useful post. Not to hijack your thread just my experience. On the foamie I built last year I ripped vinyl fence posts down making 2 lengths of vinyl angle from each and used for door frame and outside trim. I glued them in with PL 300. The trailer is used a s a hunting blind and has sat in the woods since last October. Still dry and looking good

No problem. I wanted this thread to be useful to future foamie builders looking for gluing/adhesive knowledge. I even made the title something that would be searched for by a beginner.

I think that the PL 300 would work fine and would get to a full cure with added time. This would be great for non stressed areas such as under flashing or like you did under the vinyl trim pieces you made. I did like how it flowed out of the tube and it did seem to have a good grab/hold quality to it. In my thinking is is because it flows easily and creates a good vacuum to hold the part once the part is pressed into place.

In building walls and areas of high stress I would go to the Gorilla Glue Construction Adhesive just because the dry time is so fast and the bond is so good. This allows you to move the parts around without a fear of breaking that initial bond and having to re-glue a joint that might pop under stress.

I might also add that there are a few other Construction Adhesives out there. The ones I looked at where around the same price as the GGCA. Since I was already having good luck with the GGCA I chose not to include them in this test. I found the GGCA at both Lowe's and Home Depot so I think it should be readily available in most areas. If that is not the case you might try one of these other adhesives and post your findings here.