Adhesive for poly

I want to install an under deck bag, and also some thin, comfort grip foam on my poly boats. What adhesive should I use?



I’ve used Dap Contact Cement
to glue minicell foam padding on both my plastic WW boat and wood/fiberglass/epoxy kayak with no problems. I first used some coarse grit sandpaper to roughen the area in the cockpit where the foam was to be placed, and then just followed the instructions on the can of contact cement. If you go that route, be sure to have plenty of ventilation (preferably, use it outdoors) while you’re working with the contact cement - nasty stuff to breathe! wd

Contact cement works for padding, but…
…it will not hold anything that’s under a constant outward pull, as an under-deck bag would be. While there are now some specialty adhesives that will bond to polyethylene, they’re hard to find, expensive and require an expensive mixing gun to boot. Realistically, your best bet for mounting the under-deck bag is to use screws or pop rivets through the deck. If your boat has deckline fittings on top of the deck, you may be able to install longer screws that will allow you to attach the deck bag without drilling new holes.

I realize that drilling holes in a boat is traumatic to some people, but it’s really no big deal and if that’s what your under-deck bag requires, just do it.

Be sure to get the red can.

3m products
I’d try 3m 5200. I haven’t tried It on poly boats but it is a very tenacious glue with good gap filling capacity.

How about Duramix 4040?
Anybody ever give it a shot? It’s marketed purpose is autobody structural adhesive for just about everything from sheet metal to fiberglass to interior plastic trim.

Drill and screw…
Be advised that 3m 5200 will take some time to set up (Read Days) depending on air temp etc…good stuff…but… I would tend to agree on the poly boat issue…grit your teeth and drill away :slight_smile:

I might be tempted to try some System III or West System epoxy… I’ve had good luck with it on Royalex but have never tried it on tuperware.

Don’t forget the favorite adhesive…
“Shoe Goo” has also proven to be a very good adhesive on some unknown plastics. It takes at least 24 hours to set up… but I’ve glued aluminum plates to poly foam for foot braces and they’ve never failed. It’s also sold in hardware stores as Plumbers Goo… and several other different types of “Goo”…I think they’re all the same :)…

I would still tend to drill and screw before trying to glue to tuperware.

Shoe Goo has gotten brittle in some of
my old projects where I used it as an adhesive.

Brittle Shoe Goo
Thanks for the heads up…how “old” were the projects??? any idea how long that took to get brittle?

What about some???
vinyl adhesive from maybe an auto parts store. I ahve a Northwater underdeck bag to install too. I pretty certain the instruction say to use a vinyl adhesive. I may have to email Northwater and get a recommendation from them. How muchwould it have added to the cost to include a small tube for installation. At least some brand recommendations would have helped.


Polyurethane Caulk/Ahesive
I used polyurethane caulk/adhiesive to glue in my xducer for my depth sounder and it has held up fine for several years now. You can get it at any construction supply but it takes a week to cure. Walmart sells some 1.5" wide self stick velcro that holds very well to plastics. You might want to give it a try.

Like most adhesives…
…Shoo Goo and other Goop products will only work for items that are under pressure. They won’t hold on poly’ if they’re under tension.

The issue with polyethylene is that it’s a “low energy” surface that’s impervious to most solvents.

Vinyl adhesives are no more effective than contact cement. They cannot dissolve polyethylene and therefore, won’t stick well to it.

How heavy is your transducer?
How much stress is it under, relative the the surface area that it’s bonded to? A deck bag may carry quite a bit of weight on relatively small contact points.

After reading the instructions, again…
There are two sets of instructions for the installation. The first doesn’t say for what type of boat construction. The other side has instructions for Roto-molded and poly boats. They cleary state that you have to drill and int heir words use stainless screws and nuts. I like the pop rivet idea and will probably go with that.

Now I have something to do this weekend boat wise. Woo-Hoo!

Thanks everyone for your
feedback. I think I am going to invest in a different, lower profile deck bag, and just use the adhesive for some comfort paddling:)

3M Hi-strength spray adhesive
my kids and i have have used this stuff to outfit more boats than i care to remember (my sons have gone through many wwboats). spray both surfaces let dry ~ 2 mins, spray again, dry again and stick em together.

It’s just spray contact cement
It won’t hold if it’s under tension. It’s fine for padding, but that’s about all.