Fiberglass question

[redbarron77]

I need to re-attach a metal bracket to a fiberglass panel, front end of an RV, so it gets hammered by wind.

The glue from the manufacturer let go.  It is in an area I don't want to drill to put in bolts+washers, so I thought I'd ask here for input.

Thanks in advance!

[ped]

I like using rubber well nuts and extra sealing with uv resistant silicon. Its how i mounted my solar panels.

 

To glue with fiberglass you have to rough it up good...like 80 grit. Then just use resin. Maybe lay a few layers of mat.

[ReconRat]

It's called a bonding product in industry. 3M pretty much has the market cornered in manufacturing and automotive.

Metal to fiberglass is an issue on the Corvette forums, and other fiberglass cars, and has a variety of answers. Some say epoxy, but not sure that works well on both epoxy and polyester fiberglass. But I would use epoxy of the correct type to REPAIR fiberglass to fiberglass.

Instead, people seem to use what OEMs use, 3M SMC/Fiberglass Repair Adhesive, Part# 08274 for metal to fiberglass panels. Probably strongest.

People also use 3M 08115 or 08116, which is panel to panel adhesive. Probably not quite as strong.

Or even 3M Super Fast Urathane Part# 08609, which is used for window glass to panels. Sounds weaker, not sure.

The good news, is you can just ask 3M on line, or at a 3M supply store, and they will tell you the answer. https://www.3m.com/3M/en_US/bonding-and-assembly-us/

There's also a two sided adhesive tape you can use, common in trailer applications. Handles high dynamic loads.  https://www.3m.com/3M/en_US/bonding-and-assembly-us/applications/panel-to-frame-stiffener-to-panel/

Most of the adhesives probably require clamping till set. So you'd have to rig up something to push/clamp in place. Like the rod thing that pushes and epoxies a mirror onto a windshield, and sets up overnight. Or maybe rig up a tie down strap somehow.

 

[ReconRat]

Was just thinking, the next time you fly in a Boeing 777, 787 Dreamliner or the Airbus A380, realize that the main fuselage is almost entirely adhesives, plastics and composites. Lots of carbon fiber. Wings still have metal and fasteners, which handle high loads and stresses better. Except Burt Rutan stuff, he's proving it can be done.

[motocat12]

Are you on bare fiberglass or the gel coat?

What force gets put on the bracket? is there a flange to glass over for more contact?

.

 

Edited December 23, 2018 by motocat12

[marlboro man]

I don’t know shit about Attaching bracket with Fiberglass but I fixed a Motorhome years ago that Hit a Telephone pole guide wire cut it all the way up to Center in the front it was Pretty Easy just  fiberglass mat and resin

Edited December 25, 2018 by marlboro man

[redbarron77]

3M sent me to their Automotive Aftermarket Division at 877-666-2277.  Calling them soon, will share what I find out, and when I get the work going on the RV, I'll share some pics of this little adventure.

[serpentracer]

this is old but this sort of thing is exactly what JB weld works good for.  seriously.  I worked at a mold making shop and we would often fix nicks and scratches in molds of fiberglass and metal with it. we also attached locator pins with it too.  you always need to scuff anything you want to stick together for a mechanical bond. 

Edited May 12, 2019 by serpentracer

[redbarron77]

The feedback from 3M:
"we recommend using the manufacturers adhesive, but 3M 08116 Panel Bonding Adhesive would be a secondary choice."

I have the bonding adhesive, and 3M Bondo 932 Self Adhesive Patch, and am just waiting for the temp+humidity to be a bit more stable for curing.

I'll take pics to show the success (or failure) of "Plan B".