After spending the past few days stripping, pounding, beating, tapping, and stomping on my old tailgate trying to get it straight, I finally gave up and went online. Ebay came to the rescue again...got a NOS FORD longbed tailgate that is laser straight for a bit less than the repros.

Guess I'll hang the old bent up one on the garage wall as art or something...
Since the old tailgate was in bad shape to begin with, I've been using it to try and learn some hammer/dolly skills, figuring that it was already pretty far gone anyway. Read some posts about metal working and figured the best way to learn was to go outside and get my hands dirty.

Learned a couple things worth sharing:

Working metal is kind of like smoothing out a piece of pizza dough...if you hit it with hammer directly over the dolly ("hammer on dolly"), it will push metal out to the sides and screw up surrounding areas with wrinkles and raised areas if you're not careful. I think this is what the pros mean by "stretching".

Carefully tapping with the hammer to a place offset slightly from where the dolly is on the backside ("off dolly") seems to bend the metal without much stretching. The trick is hitting in the right place, not too hard, and knowing when to stop. Some streching still happens, but not near as bad as when tapping "on dolly".

Found that the best way to raise a small dent was with the dolly on the backside of the dent, then tap lightly with the hammer around the edges of the dent, 1/4 or so beyond where the dolly is on the other sides. Got some good results with that technique.

After a steep learning curve on the tailgate, I think I'll have a better idea now how to approach the rest of the truck. Small dents I will carefully attempt to push out, but I think I'll save the bigger ones for a body man.

It sure would be alot easier if there was a simple way to shrink metal thickness in problem areas, but that seems to require special equipment and/or greater skills.

Any advice out there for an easy way to shrink?

 

It is worth the investment to purchase Ron Covell's CD, "Basic Techniques of Working with Steel". www.covell.biz

 

Thanks for your post. Very informative. I am fixing to start messing with the bed of my 49. I don't have much experience with body work but I'm ready to learn. Actually I'll be forced to learn. If you've ever read any of my posts you will know that I am a tightwad (and broke) so I will have to figure it out.
I do have a very close friend that is an excellent body man, I spent most of last year helping him build his house so I think I'll be able to get a bit of help in the trouble areas.

Thanks again for the info
Bobby

 

[QUOTE=LEckart]It is worth the investment to purchase Ron Covell's CD, "Basic Techniques of Working with Steel". www.covell.biz[/QUOTE]

I've heard good reviews of that series from Axracer and others. Once the bank account recovers from Christmas (and the gift to myself of the NOS gate ), I'll probably get it.

Until then, any other free body working tips would be greatly appreciated.

 

I'll offer you some advice as well..very seldom do you need to stretch metal during bodywork, unless you're starting from scratch on a panel that you're making...so instead of hitting directly (as you've noticed it stretches the metal) and instead of hitting it off dolly, use the hammer to graze the metal...i/e in somewhat of a sliding motion, until the metal shape is what you want...once you hear a "metal to metal" "clink or clank", don't hit any more, or you will start stretching it.

Hope you understand what I mean.

 

what 3mike6 says. When striking the panel with the body hammer, slide the hammer perpendicular of the metal as you strike at the same time of bringing the hammer back up. Light hits not big blows. It's nothing like hitting a nail. secondly, by using a file you can find high spots(paint removed) and low spots (paint left behind). It takes practice.

 

That grazing motion with the hammer was something I was trying while tapping the "rim" of a dent, pushing away from the center of the dent, with the dolly held up firmly against the backside.

It made sense with the "pizza dough" analogy in mind...trying to push the extra metal away from the dent and raise the dent indirectly with the pressure of the dolly.

I'm looking forward to learning from Covell's stuff...

 

Rob,
Here's another source of info on the web. Quite a bit of interesting reading.
www.autobody101.com.
Good Luck,
Kent

 

About 3 years ago I bought a "Sunchaser" shrinking disk. You mount it on a heavy grinder. After you have done your hammer/dolly work on the sheet metal, you heat the work with the shrink disk. The high areas will turn blue from the friction. Then you cool it with a wet rag. Only the high areas are affected. Then you do it again and again until the dent is gone. I had some good results on flat stuff. I never got good enough to do the round corners though. The side section view of the disk looks like ^^^^^^^^^^^. I have watched the demo in person several times and viewed the enclosed video tape about 5 times. I am convinced that with the proper amount of practice, the user can acheive great results. Has anybody else used this? Jag

 

Couple of helpful hints: If the dent is in an area where you can't hammer "off dolly" then you can use a resilient surface dolly with steel hammer or resilient hammer with steel dolly to reduce chance of stretching while hammering "on Dolly". Resilient dolly: purchased hard rubber or try hockey puck (shape with grinder if needed), nylon or delrin rod or nylon hammer head. Resilient faced hammer: nylon or plastic mallet, nylon faced dead-blow hammer, hard rubber faced mallet, nylon or delrin punch hit with hammer (most paintless dent repair is done off dolly with a nylon punch). Most body hammers except for the most expensive ones need the face reshaped. The face should have a smooth shallow crown to it with the edges rounded. You can use a disk sander with 80 grit then 180 grit and finally 400 grit sandpaper to shape the head, take your time to do a real good job, the better the hammer the better the work. Same with your dollys, sand them to a smooth 400 grit finish, lightly softening all edges and corners. The only time you use a flat faced hammer (with rounded edges!) is on a convex surface such as the top of a fender. If you can only afford one hammer get one with a "flat" face ~ 1-1/2" in diameter and a longish pick on the other end. Soften the end of the pick into a rounded bullet shape, not sharp pointed. The pick is used from the back of the panel off dolly to raise up small low spots, which are then smoothed with the "flat" face from the front with light on dolly work. You're not trying to hit hard enough to stretch the metal, just tap it down smooth. Find high and low spots by sanding the area lightly in one direction only with a piece of 80 grit on a sanding board or glued to a 16" long pice of 1x3 lumber, the high spots will stand out as shiny spots, the low spots as dull. Ech time you check the panel sand in a new direction or lightly dust the panel with rattlecan laquer. You can make useable body hammers out of ball peen hammers by reshaping the face as above. A slap hammer should be your next hammer purchase, or make your own from a foot long piece of leaf spring.

Shrinking can be done with an OxA torch or easier yet, if you have a 7" angle grinder, with a shrinking disk. I recommend the disk even if you have to buy a grinder to use it, it's easy to use and does a remarkably good job. You can get a disk online for 35-50.00.
My shrinking disk is just a smooth stainless steel disk.

Another highly recommended purchase is a bullseye pick.

 

Alot of very interesting information, guys...thanks.

I'll try the tips out, including the shrinking disc, on the old tailgate.

 

To shrink with a torch, put on a small tip and have your hammer and dolly handy as well as a place you can put the torch down quickly without shutting it off or a helper to take it from you. Work from the center of the stretched area. Use a small hot flame and heat an area about the size of a dime until it turns bright cherry red and humps up like a wart. Hand off the torch and lightly tap down the wart working "on dolly". The smaller the spot and the hotter it is when you tap it down the more shrinkage you'll produce. Some instructions say to quench with water or compressed air, but you'll get just as much shrink and less problems using the method above and allowing the metal to air cool. After it cools check it in both directions to see if any more shrink is required You're likely to be surprised how much shrinkage one spot will produce. If you need more shrinkage do another spot about 1-1/2" away from the first. do not overlap shrink circles. You can shrink in a spiral pattern to flatten a large oilcan, or in a line to take out a bow or pillow.

 

Hammer on, you mean you're hitting the high spot with the hammer; with the pick end?

 

Cool...something else to use my torch on!

I'll give that a shot.

 

Hammering "on dolly" or "off dolly" refers to the placement of the dolly relative to the impact spot of the hammer on the panel.
Hammering "on dolly" means the dolly is placed directly behind the spot where the hammer is hitting, sandwiching the metal between the face of the hammer and the dolly. This is characterized by a metallic ringing sound with each hammer blow. Hammering "on dolly" will thin the metal stretching it, therefore it will have more area which causes it to dome up. "On dolly" hammering is mostly used in body work to stretch a welded seam since the heat of welding will cause heat shrinkage along the seam. "On dolly" hammering is usually NOT used to repair a dent, dents are not the result of shrinkage, so if you try the straighten a dent by hammering "on dolly" you will will probably smooth the dented area, but the stretching that was produced will make the repaired area bulge up higher than it's original profile resulting in a bulge or oil-can. No amount of filler will fix a stretched bulge, and if you push in an oil-can and fill it, panel movement will eventually cause the oil-can to pop back out making a worse bulge at best or cracking and popping off the filler at worse.
Hammering "off dolly" is the proper technique for dent removal, assuming the dent didn't result in stretching the metal as well. In "off dolly" work, the dolly is placed behind the low spot of the dent (high and low relative to the front of the panel) and pushed hard against the panel. The hammer face should strike the metal on the high spot around the edge of the dent along side the dolly. This type hammer work is caracterized by a dull THUMP. The pressure from behind does most of the work by pushing the low spot out while the hammering smoothes the ripple that is trapping the dent in.

When torch shrinking you (LIGHTLY) hammer the wart down "on dolly" with the flat face of the hammer.

The pick end of the hammer (or a bullseye pick) is used "off dolly" on the BACK side of a small tight dent to push it up in small bumps , and the metal is then smoothed from the front side with the flat face of the hammer by GENTLE overlapping taps "on dolly". This light tap and move smoothing technique is called PLANISHING and the blows are only hard enough to lower the small bumps to the face of the dolly without stretching the valleys between. Planishing is characterized by a solid sound of metal on metal without ringing.