Smoothing Fiberglass Flares

['68 Coronet R/T]

I have a friend whose son is restoring a 1972 Porsche 914.
He added the flares but now wants to smooth them to the fender. His installation method was rivets as can be seen in the picture below.

Since the fenders are metal and the flares are fiberglass, what is the best method of installing them and smoothing them to the fender?

I would think they have a special panel bond adhesive for something like this.

 

[OJ86]

I have done several variations of metal to fiberglass and it almost always ghosts back. some worse than others.

The next time I do something of this nature, I am going to panel bond the parts and then use the p17 filler to feather out the transition and see how that goes.

 

['68 Coronet R/T]

Just normal panel bond adhesive then?

 

[OJ86]

Yes, Most of them from my experience will work with most materials. I usually use the heavy panel stuff. I don't know all of the part numbers off hand, but they will say what substrates they are good for on the front.

 

[RenewAP]

Yes, Most of them from my experience will work with most materials. I usually use the heavy panel stuff. I don't know all of the part numbers off hand, but they will say what substrates they are good for on the front.

Fusor 108B & 3M 8115 are the 2 most common ones I sell for all types of bonding.

 

['68 Coronet R/T]

Thanks, I appreciate the help.

 

[texasking]

I have never seen metal bond fiberglass. Not saying there is one, but I have never personally seen it. Lots of shrinkage/expansion between 2 completely different materials. Eventually will show at the very least, or crack.

 

['68 Coronet R/T]

3M 08116 claims to be work on the dissimilar surfaces.
The kid wants these flares on there so I am wondering if applying the panel adhesive and then using rivets to secure it might be the best approach?

If fiberglass doesn't bond to metal, what about the body filler that has fiberglass in it to float the gap and cover the rivets?

 

[dhutton01]

3M 08116 claims to be work on the dissimilar surfaces.
The kid wants these flares on there so I am wondering if applying the panel adhesive and then using rivets to secure it might be the best approach?

If fiberglass doesn't bond to metal, what about the body filler that has fiberglass in it to float the gap and cover the rivets?

3M 8115 is the stronger version of 8116. I have had good luck using 8115 to bond fiberglass to metal. Emphasis on luck. Rough up both surfaces real well.

Rivets to back it up seems like a good idea.

 

[jcclark]

I don't like rivets, every time I've used them they ghosted the finish
later on down the road. I usually use sheet metal screws to draw things up tight
when using panel adhesive, once set I remove the screws and fill the screw holes with the same adhesive.
Has worked good for me on patch panels.

 

[crashtech]

Don't leave rivets under the finished surface.

 

[OJ86]

yes, the rivets will show for sure.......been there, done that, lol

Like stated above, use screws to hold the part while it cures and back fill the holes with the same epoxy after.

 

[OJ86]

Also as far as filler the only filler I would use on this is vette panel adheasive or the p17. After using both I would lean more towards the Adtech P17.

If any normal duraglass or regular filler is used, on a nice sunny day you can crack a beer and discuss the lines that are appearing all over the place!