need help with knowing the strength of two part epoxy

[roy_shimp]

Does anyone know of technical papers that document the strength of screws in 2 part epoxy? I'll need the data for a sign permit. The intent is to attach 72" z-clip rails ( the rails have screw holes) to 18lb hdu by drilling slightly oversized pilot holes for the screws into the hdu, filling the holes with the 2-pt epoxy and inserting the screw thru the z-clip screw hole into the 2-pt epoxy. I sent an email requesting the info to West Systems. Waiting their response.
Thanks , Roy Shimp

[dlcw]

I would suggest contacting the manufacturer of the epoxy you will be using. They should have that data.

[joe]

Roy,

You might consider contacting one of the HDU manufacturers since all of them recommend this kind of technique. Precision Board and SignFoam and Duna HDU would be some to contact.
With HDU one of the considerations is it's density. Also, when we use this technique a burr is used to enlarge the bottom of the hole. That makes for extra holding power.

Joe

[roy_shimp]

Thank you. how do you usually make a burr?

[roy_shimp]

thank you, i'm waiting their replys

[a.werby]

It might be stronger if you used threaded inserts into the HDU, instead of expecting the glue to hold the screw threads. You can glue in the inserts: https://www.ezlok.com/

[Precision Board HDU]

Not sure if this information is too late, but we had West System test our material to destruction using their Six10 Epoxy. The results are here: http://precisionboard.com/precision-board-test-report/.

We also have a page with tips for mounting HDU signs that you might find useful here: http://precisionboard.com/sign-makin...ard-hdu-signs/.

If you have more questions, you can always call our tech support team at 800-845-0745. Thanks!

[joe]

A critical look at this question begs the point. The person asking that question wouldn't know what the proper answer is. I've been making application for sign permits in six cities and this must be the most weird question of all. But, the permit person has the control.

Few, if any, of the city officials I deal with know anything or are knowledgeable about stress loads on HDU. Not to mention about Epoxy. I would have to ask them what stress load they are looking for. It's a question posed by a slow thinker who is exercising their authority.

Joe