Adhesives for rubber and plastics?

JHZR2 · Jul 19, 2023

My evaporator drain tube is known to be a poor design as it’s made of foam.

The end that connects to the evaporator box is rubber. The narrow end fits perfectly in 3/4 tubing.

It’s not tight but it is the right fit. It needs some adhesive, perhaps inside and out.

What would be right to use? I’m thinking contact adhesive or rubber cement on the inside, and wrap with one of those self bonding silicone or urethane tapes (flex seal tape?) on the outside… maybe even electrical tape…

Thoughts/recommendations?

Thanks!

Cujet · Jul 19, 2023

If it's just a hose that's the wrong size, you could use some heat shrink around the outside. Maybe even heat shrink that has internal glue.

In some cases, rubber hoses can be glued with a quality CA glue.

You can try the Loctite plastic glue products (which are a form of CA glue) , or even Plastex (order online)(not a CA glue) or even a hot glue gun with an all purpose adhesive. Also JB Weld makes a plastic glue. I've had mixed results with it.

Pablo · Jul 19, 2023

I would try this: https://www.lowes.com/pd/DAP-RapidFuse-0-85-fl-oz-Super-Glue-Clear-Multipurpose-Adhesive/1000142517

I've bonded some odd plastics with Rapidfuze then yes one of the silicone tapes.

JHZR2 · Jul 19, 2023

Cujet said:
If it's just a hose that's the wrong size, you could use some heat shrink around the outside. Maybe even heat shrink that has internal glue.

In some cases, rubber hoses can be glued with a quality CA glue.

You can try the Loctite plastic glue products (which are a form of CA glue) , or even Plastex (order online)(not a CA glue) or even a hot glue gun with an all purpose adhesive. Also JB Weld makes a plastic glue. I've had mixed results with it.

Yes, it’s just remaking the old foam hose with something that will probably be a bit more robust and last longer. It’s just that connection/bond that I need to make so I can use the original rubber connection to the evaporator nipple, with the hardware store braided hose of whatever kind of material that is…

spasm3 · Jul 19, 2023

I like the bonding tape idea, with heat shrink over it

doitmyself · Jul 19, 2023

It's non pressure, that's good. The hose is probably reinforced clear PVC vinyl tubing -difficult to find adhesives for that. You are joining dissimilar products (vinyl/rubber).

I would be tempted to cut off the male nipple on the rubber fitting and fit a thin metal tubing nipple (aluminum, copper, brass, stainless) into each component and secure with strong cable tie or small hose clamp.

Size the vinyl tubing i.d. to match the rubber i.d.. You might find suitable barbed plastic nipples, but not necessary due to no pressure, and they will be thicker and more restrictive.

Example of tubing: https://www.acehardware.com/departments/hardware/metal-sheets-and-rods/aluminum-tubes/5267117

Lots of variations possible.

JHZR2 · Jul 19, 2023

doitmyself said:
It's non pressure, that's good. The hose is probably reinforced clear PVC vinyl tubing -difficult to find adhesives for that. You are joining dissimilar products (vinyl/rubber).

I would be tempted to cut off the male nipple on the rubber fitting and fit a thin metal tubing nipple (aluminum, copper, brass, stainless) into each component and secure with strong cable tie or small hose clamp.

Size the vinyl tubing i.d. to match the rubber i.d.. You might find suitable barbed plastic nipples, but not necessary due to no pressure, and they will be thicker and more restrictive.

Example of tubing: https://www.acehardware.com/departments/hardware/metal-sheets-and-rods/aluminum-tubes/5267117

Lots of variations possible.

Exactly my concern. Granted, I don’t know how much of a bond is necessary, assuming that there’s no practical way for the male tube to slip out of the larger diameter.

brianl703 · Jul 19, 2023

doitmyself said:
It's non pressure, that's good. The hose is probably reinforced clear PVC vinyl tubing -difficult to find adhesives for that.

HH-66:

Learn more about HH-66 Vinyl Cement - RH Adhesives

HH-66 is the world's best vinyl adhesive since it works underwater, sets in minutes, and creates durable bonds with just a single application.

rhadhesives.com

This will bond vinyl, rubber, wood, metal, and more. I believe it's a thermoplastic urethane adhesive. You can definitely apply it to two surfaces, let it dry, and then use heat to bond them.

vavavroom · Jul 20, 2023

Rubberized CA glue for a permanent bond.

https://www.amazon.com/IC-2000-Rubber-Toughened-1oz-Adhesive-Glue/dp/B0B2PQPYTV

Bob Smith Industries BSI-142 Clear Foam-Cure Craft Cure

https://www.amazon.com/Bob-Smith-Industries-BSI-142-Foam-Cure/dp/B089GTRLTS

Barge All Purpose (contact cement) for a slightly less permanant bond

Barge High Strength Cement All-Purpose Cement 2 oz - Ace Hardware

Barge has long been the adhesive of choice for leather crafting and shoe repair due to its unparalleled strength and flexibility. With a wide spectrum of bonding capabilities, applications range from resoling combat boots for active duty soldiers to creating model railroad scenery. Barge has...

www.acehardware.com

Silicone adhesive may be another decent option because it sticks well to foam.

I'd be inclined to choose the Barge glue.

ekrampitzjr · Jul 20, 2023

Here's a thought out of left field: try electricians' friction tape on the nipples. This tape has no adhesive, but holds in place exactly as the name implies. Stretch it a bit, then apply.

Cujet · Jul 20, 2023

The more I think about it, the more I believe this is a job for a hot glue gun.

wings&wheels · Jul 20, 2023

I'd try 3m 4200, pricey but very good and versatile adhesive/sealer. Clean and rough up both areas to be bonded, especially the vinyl hose. I just did something similar w'/ the same type of hose on a boat windscreen washer system.

doitmyself · Jul 20, 2023

Maybe we are over thinking this, Last night I put 4 types of caulk/adhesive on a piece of reinforced PVC poly tube: EPDM Butyl Sealant, Permatex Ultra Black RTV, Regular Silicone RTV(vinegar smell), and Shoe Goop. Cleaned tube with isopropyl first.

At 8 hours cure, all 4 are sticking tenaciously to the tube. The two silicones "seem" to edge out the others (always amazed with RTV). The butyl caulk needs more time - it takes days to cure and lose its tackiness - I used it last month on a EPDM rubber project because that is what it supposedly excells at (adhesion to rubber). Butyl caulk cures slowest while the shoe goop acts very much like contact adhesive (tacks up VERY fast).

Hmmmm, now maybe guessing what sticks to rubber is your next question. Both sides of your joint will be secured from movement, so anything that fills the gap from leakage should work. Super bonding strength is probably not needed. You could even cut some narrow half inch long slits in the poly tubing end and use a cable tie to clamp it onto the rubber fitting.

Pablo · Jul 20, 2023

I was thinking you wanted something to get in and bond the actual union of the two materials. Hence my Rapidfuse recommendation. I don't think there's a huge issue actually sticking to both vinyl and rubber. Most of the recommended adhesives will do that.

Any motion should be at the rubber I imagine. A little with the vinyl hose, but seems like you wouldn't want movement at the joint.

Fuse, then some tape for more rigidity.

vavavroom · Jul 20, 2023

ekrampitzjr said:
Here's a thought out of left field: try electricians' friction tape on the nipples. This tape has no adhesive, but holds in place exactly as the name implies. Stretch it a bit, then apply.

Friction tape makes a great wrap. It's cloth tape impregnated with a rubber adhesive.

Adhesives for rubber and plastics?

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