Adhesive Usage in Plastic Fabrication

[dholly 718]

I need to glue acrylic (Plexiglas) to aluminum. Looking for a 2-part resin with flexible properties. Any recommendations? No guessing please, this is a structural application. Thanks.

 

Note: I would like to meet or exceed the bonding properties of Weld-On IPS 45. However, in so much as this is a rather small, one-time usage, trying to avoid the cost of an applicator gun.

 

The one possibility I've found so far is Loctite Epoxy Plastic Bonder, but I can't find the compression shear strength to aluminum, only the tensile shear strength. Good news is this epoxy is available at most big box stores.

weldon-45-spec.pdf

EPXY_PLSTC_S_tds.pdf

Edited 28 Sep 2015 by dholly

[cliff 45]

What ever you use, Put a good scratch in it to give it tooth for a mechanical bond. I have done some interesting repairs with SEM panel bond. It is not flexible when dry but will stick butter to grease.

[dholly 718]

Looks like good stuff but I need the ability to withstand expansion/contraction of dissimilar substrates. Just read a bunch of great reviews for West System G/Flex 655 Epoxy Adhesive. Very interesting how sanding, alcohol wiping and 'flame treating' certain plastics can more than treble tensile shear strength.

[EDMO 1078]

Looks like good stuff but I need the ability to withstand expansion/contraction of dissimilar substrates. Just read a bunch of great reviews for West System G/Flex 655 Epoxy Adhesive. Very interesting how sanding, alcohol wiping and 'flame treating' certain plastics can more than treble tensile shear strength.

Doug,

Can you post a link to that. Sounds interesting.

EdMO

[TJay 1041]

You find something let us know it may also work for the kitfox plastic leading edge

[dholly 718]

TJay - everyone I know that used the extruded PVC leading edge applied it with Hysol, but the modulus of elasticity is not appropriate for the amount of flexing the spar endures, IMHO. I will be using Dow Corning 795 structural adhesive, it will bond plastics to aluminum and the cured sealant is durable and flexible enough to accommodate ±50 percent movement of original joint dimension. Keep in mind too, the LE will be covered and held in place by the fabric covering. More info and MDS link here ---> http://www.dowcorning.com/applications/search/default.aspx?R=264EN

 

Ed - just Google 'propane flame treating plastics', lotsa info and you will find out the real meaning of 'Cleavage Stress'.

West System G/Flex 655 Epoxy Adhesive info link here ---> http://www.westsystem.com/ss/west-system-launches-g-flex-epoxy/

[akflyer 1427]

5200 is hard to beat for installing the leading edge plastic.

[Luked 71]

Hey Doug, some of the RV guys use a product called Sika Flex to glue their bubble canopies on to their aluminum frames. There is a lot of info over on the Vans Airforce forum.

 

https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=sika+site:www.vansairforce.com

[dholly 718]

Thank you...

[Av8r3400 1178]

Sika is the adhesive manufacturer that I use in my windshield business.  Sika-Flex is one of the lower grade automotive window adhesives.  I am currently using their "Mach 60" product, which is their latest and greatest adhesive.

 

Doug, what is the application you are trying to accomplish?

[dholly 718]

Aluminum mounting bracket to acrylic windshield.

[Av8r3400 1178]

Try calling a local auto glass shop.  You may be able to get a tube of urethane from them along with the necessary primer and activator chems.

[TJay 1041]

 I have also seen that stuff at Arnold Motor Supply which is just an auto parts store.

[dholly 718]

Doug,

Can you post a link to that [Flame Treating Plastics]. Sounds interesting.

EdMO

I was on an out of town trip to visit one of my kids last week and spied a West Marine Store. We don't have them here so I thought it would be a great opportunity to get some info on West System G/Flex 655 Epoxy Adhesive, straight from the 'horse's mouth' so to speak. Geez, why is it that more often than not you know more about a company's products than their own representatives? The store manager was USELESS! Hell, I can read the damn labels too... They were, however, pretty proud of their products despite their lack of knowledge, as the bill for the epoxy and (8) reusable plastic mixing sticks was $32.

Since they only had quart kits available, but my little project and the product shelf life is such that the vast majority would end up in the trash, I looked around and found another flexible epoxy that supposedly bonds aluminum to both acrylic and poly-carbonate called Marine tex "FlexSet", manufactured by ITW Polymer Technologies. On the back of the blister pack was directions for bonding polyethylene using Flame Treating, see attached.

Now trying to decipher the Tech and MSDS sheets on the two products to see which may be the best choice. Admittedly, I don't have a clue so anyone knowledgeable about this stuff willing to compare and offer comments would be a help. Thanks.