[cc82z-28]

I've got a question for you body shop gurus out there, I have bonded an L88 fiberglass scoop to my original hood that came on my 82 Z-28. It is one of those SMC type hoods and I used 3-M's 8116 bonding epoxy to do so and I am going to be sanding and filling to feather out the lines to blend in. I feathered out the product when I did the bonding to blend into the hood as much as possible, my question is this, what filler product is recommended to do the final filling and feathering? I've heard that fillers will not stick to these types of epoxy, is that true and if so what do others do? Thanks for you help.

[bigdog7373]

Originally Posted by cc82z-28

I've got a question for you body shop gurus out there, I have bonded an L88 fiberglass scoop to my original hood that came on my 82 Z-28. It is one of those SMC type hoods and I used 3-M's 8116 bonding epoxy to do so and I am going to be sanding and filling to feather out the lines to blend in. I feathered out the product when I did the bonding to blend into the hood as much as possible, my question is this, what filler product is recommended to do the final filling and feathering? I've heard that fillers will not stick to these types of epoxy, is that true and if so what do others do? Thanks for you help.

I've heard of people using primer over the fiberglass then using the filler. Don't take that for 100% though, since i've never personally done this. But that's what the import guys do with their body kits and what not and it seems to work good for them.

[69 widetrack]

3M's 8115, 8116 etc. don't have an adhesion problem with filler. These products, if I am correct, are labeled "Panel Bond Adhesive" and are used for installing quarter panels, door skins, even the roof on cars. I have used filler over top many times and not had an adhesion issue. The issue I have had is the junction line coming back after paint especially if fiberglass is used instead of filler. To help minimize this reaction allow extra time for the Panel Bond Adhesive to cure, depending on what you use, 8115 or 8116, they have different cure times. Just give them an extra few hours...like maybe 6 hours extra time for insurance. I have used Rage Gold with excellent results, finish your filler extra fine (I finish mine in 320 grit) and Prime with a 2 part catalyzed primer. Ensure proper flash times are allowed between coats (and then give it another 5 to 10 minutes, just for even more insurance). Block sand and paint....you now have an invisible repair.

All the best
Ray

[Old Fool]

If you have any doubts, put two coats of SPI epoxy on it, then use what ever filler you choose. Cone properly it will be stuck like glue (pun intended).

[tech69]

I'd use an adhesive repair that's ok for fiberglass and SMC repairs. 3M's 8243 works well for this. If you groove it out nice you can lay a nice bed of this stuff and top coat with a flexible filler like an Evercoat Polyflex. The concern with this repair is differing expansion and contraction rates so if you use the right products you don't have lines showing up or anything. I wouldn't use a poly primer for the hood but a urethane 2k with flex additive would be ideal, but the 2K urethanes have a tad of flex by themselves.

[cc82z-28]

Originally Posted by 69 widetrack

3M's 8115, 8116 etc. don't have an adhesion problem with filler. These products, if I am correct, are labeled "Panel Bond Adhesive" and are used for installing quarter panels, door skins, even the roof on cars. I have used filler over top many times and not had an adhesion issue. The issue I have had is the junction line coming back after paint especially if fiberglass is used instead of filler. To help minimize this reaction allow extra time for the Panel Bond Adhesive to cure, depending on what you use, 8115 or 8116, they have different cure times. Just give them an extra few hours...like maybe 6 hours extra time for insurance. I have used Rage Gold with excellent results, finish your filler extra fine (I finish mine in 320 grit) and Prime with a 2 part catalyzed primer. Ensure proper flash times are allowed between coats (and then give it another 5 to 10 minutes, just for even more insurance). Block sand and paint....you now have an invisible repair.

All the best
Ray

Thanks to all who chimed in, the scoop has been bonded on sincethis past Sunday, so it has had plenty time to cure and I will probably get back to it this weekend. Funny thing, I contacted 3-M and they said they couldn't advise using this product to do what I did and I am thinking really? It's ok for quarters, roofs door skins etc but should not use for a hood scoop? They said I should buy a 1 piece fiberglass hood with the scoop of my choice, that completely goes against what I was trying to do in using an existing hood that is 'glass and save a ton of money. So they wouldn't recommend a filler to use to finish off the job, strange I thought, and that is why I came here for some ideas and the people here have never let me down. The 8116 adhesive is rated for SMC and fiberglass bonding and that is why I used it. It is stuck and I don't feel it is going anywhere and since the hood and scoop are in essance both glass, should be fine with no cracks. I just wanted to be sure I could use something that would work over any epoxy that doesn't get removed through the first sanding. Thanks again.

[69 widetrack]

Incredible...You got the wrong guy at 3M. I used to do seminars with a local 3M rep specifically regarding this type of application and that was over 10 years ago. I think if it worked then it will work now...I've said it before and I'll say it again..."Life is the easiest thing you will ever go through, it's only people that get in the way".

[cc82z-28]

Originally Posted by 69 widetrack

Incredible...You got the wrong guy at 3M. I used to do seminars with a local 3M rep specifically regarding this type of application and that was over 10 years ago. I think if it worked then it will work now...I've said it before and I'll say it again..."Life is the easiest thing you will ever go through, it's only people that get in the way".

Yea, I found it hard to believe that what he said that as well, he even stated to remove the product to heat to 400* soften, I guess to remove. I guess he forgot the part about the part in my email that said it was an SMC plastic hood and fiberglass scoop, both which would melt/burn. Thanks to all who chimed in for suggestions, much appreciated.

[69 widetrack]

Good luck with your project. The products that you have used will work fine...I would have recommended that exact product to you even prior to your posting.

Best to you
Ray