Good Coroplast to Coroplast Adhesive?

[garys_1k]

I want to patch up some "oops" and bond some lap joints together. What's a good glue to hold this stuff to itself?

[Daox]

I'd give super glue a try.

[metroschultz]

I was wondering that very same question.
I was going to try using 3M spray trim adhesive (I have 2 partial cans on a shelf) That stuff seems to be able to hold just about anything to itself.
My other thought was to carry some coroplast to the craft store or home depot and ask them for advice.
And now a 3rd thought, asking the people who sold me the coroplast in the first place. They ought to know.
Shultz

[reformed]

I'd try liquid nails or possibly gorilla glue.

[MetroMPG]

I've used contact / rubber cement with coroplast (once). Worked well for me.

[basjoos]

Coroplast is made of polyethylene, so you need to use one of the few adhesives that will work with polyethylene, which is a low surface energy material that most glues will only attach weakly too. If you are careful, (since coroplast is hollow) you can also heat weld pieces of it together. McMaster-Carr sells an epoxy adhesive that works with polyethylene.

[wagonman76]

Walmart sells a 2 part glue (primer + glue) that says it works even with polyethylene. I know it is rare to find one that does work. Honestly Id try contact cement first, it seems like it would work a lot better for large surface area lap joints.

[garys_1k]

Thanks for the info. on just what coroplast really is, basjos. I found some information about bonding polyethylene by googling and found this writeup about a specialty 3M product, DP 8005:

http://www.stealth316.com/2-dp8005.htm

He talks about the special applicator -- I'd give just squirting it out on a piece of cardboard and stirring it up a try. It looks like it's available at "drillspot.com" here:

http://www.drillspot.com/products/32...astic_Adhesive

With ground shipping a single tube is about $25.00. I may want to live with my ugly lap joint for a while, or even try some really short sheet metal screws run in from the piece behind the visible surface to see it that's good enough for a while.

Edit to add: Sheesh, thanks again, basjos, for the McMaster-Carr reference. I'll see if the outlet near me stocks the stuff.

[Meph]

construction adhesive works well for most anything

[ebacherville]

you should try fiberglass resin on a sample piece.. bet it would work, there are different types of resins that are compatible with different types of materials..

Really i love fiberglass resin there are so many uses for the stuff.

[capoed84]

I've used contact cement. It bonds very firmly so make sure the pieces you are bonding are perfectly lined up because it is not very forgiving if you have to start over.

[skyl4rk]

I tried two adhesives which I use for boatbuilding.

I cut 6" x 6" squares from a coroplast sign and glued the squares together with about a one inch overlap. I applied the glue and then drove 2 deck screws through the joint to clamp it together. Then left it without touching it overnight.

1. Two part epoxy, similar to WEST System. Cured 24 hours. I was able to pull the pieces apart, but it took quite a bit of effort. The plastic bent much easier than the force needed to pull the two parts apart. Where there was paint from the sign graphics, the epoxy pulled the paint off of the coroplast. The pieces would probably hold together in most high speed wind conditions. Using a fastener like a bolt or rivet on the ends would likely help keep the pieces together in high stress conditions. I did not wipe the joint with acetone first, that might help improve adhesion. I did not scuff the joint with sandpaper, that might help too.

2. PL Concrete and Masonry Sealer. This is a polyurethane caulk which is used by boatbuilders as a glue because it is relatively cheap and works as well as other polyurethane glues like 3M 5200. After 24 hours, the joint had not cured completely. I believe that this is because polyurethane needs moisture in the air to cure, or maybe it just needs air. Perhaps misting the joint with water would help cure time. Perhaps using only a small amount of adhesive in a thin layer would work best. I put the two parts back together and let it cure an additional 48 hours. It held together quite tightly and took a lot of effort to pull apart, similar to the epoxy. The center of the joint was not cured completely. This adhesive would also work although you would probably need to allow it to cure for a week or more. I also tried an end to end joint, applying the glue to the end of one piece and pushing another piece against it in a butt joint. With no over lap and just the 4mm width of the two pieces touching, it was actually a decent join, not too difficult to tear apart but surprisingly tough. I tested it after 36 hours of cure time.

I tried a pop rivet on the coroplast, and it would work if you used a washer or some hard material on either end of the rivet. The rivet would pull through when trying to rivet two layers of coroplast with no backing. I don't like pop rivets much because they have an ugly side to them on the inside, but it would be one way to fasten a joint. Another type of fastener that would work with coroplast is to use zip ties, but they are quite flexible and probably would not work well together with adhesive. Deck screws with large threads worked well but then you have the points on the inside to deal with. Maybe light nuts and bolts with plastic washers might be the ideal fastener to use together with adhesive.

[Blue07CivicEX]

On the subject of Zip Ties, they work quite well with coroplast, I was able to make slits along the corrugation and run the zip tie inside the coroplast without coming through the front then tying it to whatever i needed. This is how I fasted my front fog lamp covers and grill block. The fog lamps used zip ties connected to an I-bolt this allowed me to get everything tucked where it needed to be then tighten the bolt from the back of the bumper (I had to drill a hole in the fog lamp holder spot but it's not too devastating).

The zip ties work great and allow for the modifications to be removed without any damage to the car except the hole in the blank fog lamp things but like i said, not too concerned about those. Also it provides for a smooth outer layer with no fasteners sticking through the coroplast.