[vanderstephen]

I will be building a set of enclosures soon for a custom kit that I am purchasing. I plan to use phenolic resin for the cabinet structure and will end up wanting to veneer it. The problem is, all of the veneer glues that I've seen state that they are for two non-porous surfaces (phenolic resin is not). I have a partial plan in place and will need help with the rest. I will apply the veneer directly to .25" MDF sheets for the sake of having a surface that is optimal for veneering. Any thoughts for how to bond MDF to phenolic resin? For those that have not worked with phenolic resin, then my question would be what would you use to bond MDF to Formica/ plastic laminate (the surface layers are effectively the same)?
My next question is what is the minimal radius for wrapping a veneer around a corner?

Thanks!

[Mark Korda]

Hi Vanderstephen,I thought this was the most helpful to me...............Mark Korda(http://www.ohio.edu/people/schneidw/audio/veneering.html) It might help answer your question..Mark.

[charmerci]

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[Vapor Audio]

I use different typed of phenolics all the time.  To bond use epoxy, West Systems is the best.  Mix either 403 or 404 filler for max bond strength. 

[WireNut]

I use different typed of phenolics all the time.  To bond use epoxy, West Systems is the best.  Mix either 403 or 404 filler for max bond strength.

Bang, That's it. I've been using West System epoxy since the 80's. It don't get any better then this. You can buy it at Rockler if you have one in your area. I like to use the 105 resin with either the 205 fast hardener or 206 slow hardener with the 406 filler. If you get the 406 or 403 filler you can always add more to make the epoxy thicker. All the speakers cabinet's I've built since the 80's I've used West system epoxy. It's also fantastic as a gap filler if your wood working skill's like mine are not the greatest.
It's awesome stuff. 

http://www.westsystem.com/ss/the-105-system/


 

[Vapor Audio]

Forgot to mention that if you'll probably want to heavily scuff the face of the phenolic sheet, 40 or 80 grit.  The epoxy will need something to bite into. 

[WireNut]

It also comes in smaller sizes.

[WireNut]

Vanderstephen,

Since you are Bonding and not Filling you may not need to use the fillers. Just the resin and hardener alone will have a consistency similar to molasses, add fillers as needed. Apply to both surfaces and lightly clamp or just add weight so  not to squeeze out the epoxy. The cans are calibrated by size, group A, B,or C. One squirt of resin to one squirt of hardener. The cans may come with the pumps but if not get the 300 Mini Pump Set.

Steve 
   

[Vapor Audio]

No, you want to use one of the high strength fillers when bonding phenolic.  The fillers are for more than just gap filling, they can greatly increase bond strength as well.  Trust me from experience, no filler with phenolic and you'll likely have a problem.

[WireNut]

Wetting both surfaces by applying a mixture of resin/hardener, then mixing up a second batch with the added fillers and applying will give excellent results.

[vanderstephen]

All great feedback so far. I have some knowledge of using the two part epoxy. It is used at my work to apply backsplashes on phenolic resin countertops. Is Smooth-on's 2part epoxy similar to West's? I could possibly get the Smooth brand for free. How much coverage do i need to bond the phenolic panel to the MDF? If full coverage is needed, would you use something like a .125" v-notch trowel? Geez, that would be a lot of 2part epoxy...

[WireNut]

The beauty of West System Epoxy IMO is not only can you use it as a 2 part epoxy but by adding fillers you can change the density from something like syrup to peanut butter or puddy as well as getting the added strength provided by the fillers. Myself, I would wet both surfaces with 100% coverage of the epoxy/hardener, followed by a mix with a filler as needed. If you can get the Smooth-on for free you could always try adding one of the West System fillers to it for around $10 bucks and do some experimenting on scrap pieces.

[vanderstephen]

I contacted West Systems and they suggested their G-Flex 655 in lieu of the 105 series. I guess the thought is that the Trespa (phenolic resin) panels have zero linear expansion, but the MDF may have some. Is there any concern about the MDF outer panel wanting to shear off of the phenolic panel due to seasonal movement. The largest size panel I will have is roughly 44"h x 18"w. Hopefully I am just over thinking it, but I've created issues for myself on a previous project using contrasting species of solid hardwoods. I can always go the automotive paint route if needed - directly on the phenolic, skipping the MDF.
Thanks!

[Bob in St. Louis]

Hi Vanderstephen,I thought this was the most helpful to me...............Mark Korda(http://www.ohio.edu/people/schneidw/audio/veneering.html) It might help answer your question..Mark.

There's a lot of good information there, thank you.

[WireNut]

Stickly Sail Inc uses West Systems epoxy in building of their sail boats which are exposed to extreme weather conditions. Doesn't seem like there would be a problem for loudspeakers in a home environment setting.

A concern about the G-Flex 655 is the cost and size of the bottles available. Looks like it may only be available in 4 or 8oz bottles as opposed to pints,quarts,and gallons of the 105 epoxy system.