I have been reading into how to properly use a hammer and dolly, but I seem to get conflicting answers. One I have read is you put the dolly behind the dent and hit it with the hammer stretching the metal and pulling it up towards the hammer. The other way I have read is hammering it out from the back with the dolly on the outside. Which is correct?
both it all depends on what you are trying to accomplish with each style used.... (basic nutshell answer)
the metal doesn't know which is the hammer and which is the dolly, whichever way is easiest to reach will work. just got to hit it different.
many different ways to do it... hammer ON dolly, hammer OFF dolly, hammer only... unless you have someone to teach you, its all trial and error. practice practice practice
Here is the short story: There are only 2 things you can do to metal to produce a compound shape, shrink it or stretch it. Hammering on-dolly, the dolly tight against the panel and the hammer hitting it making a pronounced "ding", will stretch the metal. You don't want to do this unless you have a specific reason. For dent repair I generally bump the metal up from behind with a dolly, although you *can* use a hammer, just be sure not to stretch it and mark it up. Feel the panel, there will be high spots and low spots. Push the dolly against a low spot and hit an adjacent high spot, this if "off dolly". Most of the actual dent repair is done this way. When the metal is close you have to make some judgment calls. Sometimes you will need to shrink a high spot (torch or shriniking disc or maybe a cold shrink), sometimes you will need to raise a low spot by stretching (on-dolly) Get a copy of the Frank Sargent book, Eastwood used to sell it (it's a little thin red paperback, it covers this in good detail) Get a Ron Covell video, like "Basic Metalshaping with Steel".
yes also remember hammer on will stretch the metal unless the hammer is a wooden hammer( again nutshell answer). every strike to the metal counts so make sure you accomplish what you want to accomplish and yes unless you have someone there it will be trial and error (sometimes the best way)
Hey, What have you been reading? Most of the auto body repair books written after 1970 don't cover "real" metal bumping & metalfinishing! I was given a copy of the " Keys To Metal Bumping" by Frank Sargent nearly fourty years ago, and haven't seen anything for the money that will beat it! Generally, ya wanna select a dolly that's shape most closely matches the inside shape of the panel you're tryin' to straighten. Think of a dolly as a hand held anvil. As pointed out above, striking the dolly with the hammer, with the metal inbetween, directly over the dolly (on dolly) will cause stretching if you're not carefull. Sometimes this stretching is necessary, as metal that has become compressed (shrunk), as in buckled or folded metal in a dent, will require stretching/forming over the dolly to return the metal to its required shape. There are times when a dolly will be used outside the panel you're straightening, such as to straighten a flange, but usually a dolly is used beneth the dent to drive up the dent , whyle using the body hammer to drive down high areas, over and around the dolly. S****ey Devils C.C. "Spending A Nation Into Generational Debt Is Not An Act Of Comp***ion!"
Actually the dent is already stretched metal, what you want to do is to shrink the metal back into the shape. It's hard to explain in a short reply. As Pimpin' Paint said get " Keys To Metal Bumping" by Frank Sargent Hunh? Sorry but that is incredibly wrong. I shrink with a metal hammer all the time, it's all in the technique.
Hey Joe! Nice to see you here! The web site looks great. Danny, I have posted some hammer and dolly work in my you tube videos below: Custom Metal Bodywork parts 1, 9, 10, 11, and 12. Also see this link to an article, with links to Wray Schelin and Ron Covell articles on the subject: http://metalshapers.org/101/jkelly/index.html John www.ghiaspecialties.com
Hey Dan - for now keep it simple. Hammering ON DOLLY will potentially stretch the metal. Hammering OFF DOLLY will help you "move" the metal with less risk of stretching. If you hammer ON DOLLY using a soft hammer then you're alot less likely to stretch the metal. The BEST ADVICE I ever got was to GO SLOW - and WORK the dents out slowly -numerous smaller hits being better (more controllable) than fewer BIG HITS. Think of the metal "unfolding" like in the Christine Movie - that's what you need to visualize as you approach metal bumping. Any HARD FOLDS or serious creases may need annealing - practicing on some s**** is invaluable. Post up some pics of what you're working on and I'm sure you'll get some great advice. P.S. You fire it up yet????
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