77 firebird endura bumper cover restoration

Schroeder

Promoted Users
I striped my rear bumper cover with a surface conditioner on an angle grinder prior to blasting. I thought this would save time and blasting media, but it probably screwed me BIGLY. I gouged the hell out of it. Well I think it was me. It could have been the previous owner because the entire thing was covered in filler. It wasn't the right filler either. It wasn't one of the flexible variants like 3m EZ sand. Here's the damage!!!
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I'm planning on putting a skim coat of 3M EZ sand over the entire thing and sanding down. I'll tape all the lines, sand up to em, and get em straight like other body lines. That's the plan anyway. Prior to putting the EZ sand down do I need to clean this with 700 WB w&g remover, or can I just put the stuff down? Again, this was just blasted with black beauty. Here's the plan right now without having received your input:

1.) Put 3M EZ sand down directly over blasted surface. (no 700 wipe down snd 24hr wait)

2.) Sand down and get straight while the cover is bolted to the bumper and on the car.

3.) Sand with 80g

4.) Wipe with 700 WB W&G remover. Wait 24 hours.

5.) Spray with 4 coats of SPI epoxy.

6.) Allow to cure minimum of 72 hours.

7.) Sand with 180g and blow off.

8.) Do all filler and body work on bumper cover.

9.) Allow fillers to cure minimum of 48 hours.

10.) Sand again with 180g, blow off, (no degreasing product wipe down this time?) spray with reduced sealer coat of SPI epoxy?

How's that sound? Am I an idiot for trying to save this bumper cover at this point?
 
I would just do multiple rounds of epoxy and blocking. Four or five coats at a time.

Don
Thanks don. Some of these gouges are pretty deep though. Maybe 1/16 - 1/32" deep. That's a bit much for epoxy isn't it?
Also, I need to use the 3M EZ sand to build up the side flange faces to be completely planar and have perfect gaps with the quarters anyway, so I thought I'd just coat the whole thing while I was at at. With that said, what do you think about the steps I've laid out?
 
I’ve always just used epoxy so I can’t comment on your proposal except I would try to keep fillers to the absolute minimum. Hopefully one of the pros will respond.

Don
 
IIRC, that EZ sand was not very user friendly. That is why I still have a partial tube from several years ago :) I would be hesitant to put it on the flange, especially, but it may work. At this point, I would da with 80# to get some of the gouges shallower, then go over that with 180# before a final wet sand with 320. Clean with Dawn on a scotchbrite, rinse, and put it out in the sun for a day. 3 coats of epoxy, induced overnight, with 30 minutes between coats. Wait 48 hrs., then do any filler work, keeping it as thin as possible. As Don mentioned above, epoxy is best and can be applied as thick as needed 2-3 coats at a time.
 
You guys know that's urethane and not Endura, right? 2 part repair materials have excellent adhesion to it. As far as I can tell, that cover is really hammered and it's going to take a lot of material to level it. I would just go straight to the repair material and get it close before primer. This is not an instance where epoxy is going to help either the integrity of the material or increase adhesion in any significant way. JMHO.
 
You guys know that's urethane and not Endura, right? 2 part repair materials have excellent adhesion to it. As far as I can tell, that cover is really hammered and it's going to take a lot of material to level it. I would just go straight to the repair material and get it close before primer. This is not an instance where epoxy is going to help either the integrity of the material or increase adhesion in any significant way. JMHO.
I used epoxy on these and they were pretty rough. The pics are in epoxy. Sometimes things work out ok when you have no idea what you are doing :)
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Don
 
411 is for very minor imperfections only, it would not be suitable for the first pass in this instance.
I guess I must be seeing something in those photos that nobody else is.
I'm seeing some really serious gouging that is going to require a coat or two of repair material over almost the entire bumper.
 
411 is for very minor imperfections only, it would not be suitable for the first pass in this instance.
I guess I must be seeing something in those photos that nobody else is.
I'm seeing some really serious gouging that is going to require a coat or two of repair material over almost the entire bumper.
Agreed they are deep and will require some filler.

Don
 
I'm not pro like some of these guys, just a weekend warrior, but I've been working on front and rear bumper covers for a 87 Camaro and used Polyvance Flex Filler 2 (part# 2000) for any spots with issues. It has worked well and like how it sands after 30-45 minutes but feel it gets much harder to sand if you don't get to it within a few hours.
 
Idk why I didn't get notifications from all the good replies you guys gave. Thanks. Crashtech is right. This was gouged way too much for epoxy to get it. It'd have taken me 87 coats.

Crash asked what the EZ sand part number was. It's 3M 05891. I have the applicator version I'm going to get into today and it's 05895. These are covered in different threads here on the SPI forums and at least one guys YouTube video series on his endura bumper repair. I didn't realize I had urethane. I can use other products? Is the polyvance a good fit for this?is it wise to put it on top of or near the cured 3M product? Is the polyvance more readily available? This 3M stuff is very hard to by right now. I think there are production shortages due to the response to the scamdemic.

Anyway, take a look at the pics of me sanding. I think things actually may level out with a lot of epoxy coats at this point. Is there anything obviously stupid that I'm doing here? I'm becoming a body man in this process! I have no experience with any of this!!!! I'm just a guy learning as I go!

Here are some pics of it coated in the ez sand flexible filler after it cured. Then there are more pics of how the sanding is coming today.
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Make sure you scratch up any unsanded material before proceeding so you get good adhesion, other than that it looks like you are good.
 
90% done sanding. 10% remains only because I just got the 1st coat of the EZ sand epoxy (pretty sure this stuff is a really expensive JB weld lol) wiped on. I embedded the new mounting plates. The old ones' bolts were busted off and the plates themselves were rotted. I fabbed and coated with SPI epoxy. The new brackets had holes through them to really merge with the ez sand and bumper cover. See the backside of the cover where I drilled through it too. The ez sand was pushed through the holes to really give some positive engagement with the cover. When cured it will have "fingers" reaching through the backside of the cover and through the plates themselves that I fabbed.
I did this because I was worried the plates would pull themselves and the top layer of the ez sand material right off the bumper cover when I bolted it up tight to the car.
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I thought I should let everyone here and anyone whose looking up the 3M EZ sand flexible filler product (05891, 05895, 05887, and maybe a couple I've missed) in the future know that the stuff is awesome. I used in on my urethane bumper cover. I had a crack/tear where the main rear face of the cover wraps around the side of the car to what I call the "bumper cover side flange". I split it out a little bit further just to fill with EZ sand and see what happened. If it failed I don't think the tear would matter as it's in an inconspicuous spot and is otherwise well supported.

I filled the v-groove, let it set up, and was trying to split it again by pulling on the flange. I used moderate pressure. I couldn't believe it didn't delaminate. I mounted the bumper with the cover to the car. I tightened down the embedded flange bolts to the car. They did not pull out. I'm surprised and amazed. Prior to purchasing I had no belief that this stuff would work. I thought it would be a mess that separated and delaminated from the urethane. Much to my pleasant surprise it seems to really merge with the urethane (which I thought was endura). I have to hand it to 3M, this stuff is awesome. I hope this helps someone looking the stuff up in the future.
 
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