[Lizer]

I have a 67 Mustang coupe. One of my first threads here was about repairing some dents in the roof. I have since repaired those to the best of my abilities and skimmed over them with filler.

However, when I run my flat hand over the roof (the filled areas are on the edges) in the middle where the panel is wide open, I feel many waves. I can't see them, but I can feel them. I'm sure once the shiny epoxy coat goes on they'll dance at me.

The roof is bare metal right now. Is this something that all the blocking and building primer in the world isn't going to fix? I spray all SPI. What are the fixes for this?

[50bowTie]

try and get a straight edge across it to judge the depth of these "waves", if you're more than 1/16ish then you may need to re-skin the roof. Go get yourself a long durablock! (can't recall the length of mine but its 2 1/2 to 3 feet long.) guide coat and long strokes will let you know if its repairable.

good luck.

[tech69]

well at least your filler is at the edges where it's tight and won't affect the middle as much. I'd block on the metal like this //// with 80 grit and then get a good look at what you got going. You can also use a sharpy and make a little grid as your guide coat, or just use the scratches in the metal. Then you can push up on your lows while tapping down on the adjacent highs. You can also hammer from below and push from above. Once you got all the areas then take a flat tear drop mallet/ finishing hammer and dolly/ shot bag and smooth it out. You can also smooth it out from both sides. Then guide coat like this \\\ which is the opposite direction from the last scratches you left which makes it easier to identify. Then repeat til it's straight and more stiff.
Roofs are a pain but when you have access to both sides it just takes a little more time to get it right and it's worth it cause you not only leave yourself with less dust in your garage but you give it the proper flex back. Shrinking disks work well with roofs to finish off.

[deadbodyman]

It'll be much easier on you if you epoxy the metal first,use a sandable epoxy then guide coat the epoxy.After everything has cured start blocking and you'll see just how bad it is.The centers of a roof can be very flimsy so It'll be nearly impossable to sand any bondo without it flexing ,so to make life easier you'll need to reinforce the inside to stiffen it up enough to sand.Theres a lot of ways to do this ,like gluing paint paddles to the inside.The method I like (because I have a wood shop at hand) is to cut long lengths of wood at the thickness and width of a paint paddle but long enough to reach from one end to the other,use hot glue or if you can, wedge them into a channel with no glue.space them about 6" apart and your all set...I always remove them afterwards but its up to you.

[OneMoreTime]

To me this would be an ideal time to use the shrinking disk as the metal is likely stretched because the roof was dented..The shrinking disk will tighten things up for you..

Sam

[oldschool hero]

I am not a proffesional body man but I have a few paint jobs under my belt and just to add my two cents for what it's worth,I use a hankerchief under my hand when feeling for waves and don't look at what I'm feeling.The best way to block that I have found is use a cross hatch pattern when blocking.Try the hanky trick,you may be surprised.

[Lizer]

I do use the hanky trick (actually use a shop towel, but same thing) and it works great. I also shut my eyes and turn my head when I feel so my eyes don't play tricks on me and can concentrate strickly on what I'm feeling.

I have a shrinking disc but it's only a 4.5" one, and my main problem is I think my angle grinder shaft is slightly bent so it has a slight wobble to it. You can't really see it just by looking at it, but on the surface of the shrinking disc you can tell only half of the disc is actually making contact with the metal so I don't think I'm making the metal as hot as I could be. Additionally, the metal gets this black marred look on it after I've used the disc. I'm not sure if I'm doing something wrong (I squirt water with dish soap on the surface as lubricant as stated in the instructions). Also, I am wondering if the 4.5" is just too small to be of any practical use. I'm sure most of you here would say yes.

I'll try out some of these ideas. I'm glad I can put the epoxy on first and then guide coat, because I'd like to get the epoxy on sooner than later.

I don't have a finishing hammer but I do have a nice slapper. I understand this can serve the function too? I don't have a shot bag either, is this something you guys highly recommend I get?

[oldschool hero]

Power tools are OK for roughing in but thats all, I do all mine by hand and elbow grease.Thakes longer but is more accurate and less boo boos.

[tech69]

Originally Posted by Lizer

I do use the hanky trick (actually use a shop towel, but same thing) and it works great. I also shut my eyes and turn my head when I feel so my eyes don't play tricks on me and can concentrate strickly on what I'm feeling.

I have a shrinking disc but it's only a 4.5" one, and my main problem is I think my angle grinder shaft is slightly bent so it has a slight wobble to it. You can't really see it just by looking at it, but on the surface of the shrinking disc you can tell only half of the disc is actually making contact with the metal so I don't think I'm making the metal as hot as I could be. Additionally, the metal gets this black marred look on it after I've used the disc. I'm not sure if I'm doing something wrong (I squirt water with dish soap on the surface as lubricant as stated in the instructions). Also, I am wondering if the 4.5" is just too small to be of any practical use. I'm sure most of you here would say yes.

I'll try out some of these ideas. I'm glad I can put the epoxy on first and then guide coat, because I'd like to get the epoxy on sooner than later.

I don't have a finishing hammer but I do have a nice slapper. I understand this can serve the function too? I don't have a shot bag either, is this something you guys highly recommend I get?

I highly recommend a shot bag with a plastic tear drop mallet with a shaved face that's nearly flat. The problem with hammer and dolly is that you can over stretch. Before you epoxy you can also kind of rough it out a bit so you can better utilize your epoxy. I tend to find that for roofs when you think it's stretched it might not even be the case cause the arch is what gives it the strength and once something in the middle is displaced it can make you think it's stretched. Sometimes just working it out will tighten up cause it gives it back the arch, but it's always good to finish with a shrinking disk anyways for those. I'm not sure about shrinking disks on hoods or decklids though. I've gotten a lot better since trying it last time on those but my take was that since I didn't take enough time to fix everything really good and parts of the skin are adhered to the supports that it can have adverse affects. Not sure though so I will try it again when time allows.

[deadbodyman]

Originally Posted by tech69

but my take was that since I didn't take enough time to fix everything really good and parts of the skin are adhered to the supports that it can have adverse affects. Not sure though so I will try it again when time allows.

Your right ,the adheasive will prevent the metal from moving the way its supposed too.When I have a bad hood The first thing I do is slice through those with my mini saw,I just use a full size hack saw blade in it,after I'm done with the bodywork I'll reglue it...

[tech69]

you're certainly right about that. I had to learn the hard way. I also feel that near the hinges of decklids the glue will continuously pull the outer skin down after you open it a few times and let the hinges stop the hood. My boss thought I was crazy when I said the ding came back.