|12-16-2012 01:13 PM|
|tech69||hmmm...never tried that. Outta give it a try. We just had a Subaru that had hail damage and it was worst on the hood. No matter how light I tried to shrink the stretch the work kept spreading and spreading. One tiny dent ended up being an area of filler almost 1/4 of the hood. Then again, you forget how flimsy and sensitive the newer metals are when you constantly work on hot rods. I'm thinking that pencil torch could have helped me some.|
|12-16-2012 01:04 PM|
The problem with stretched metal is realising just exactly how much stretch is involved.
Most times the heat/quench method is just too much.
On hail dents, the metal is surely stretched, but the dents can be easilly removed with a pencil torch, and not quenching. Sometimes without even damaging the paint.
|12-14-2012 04:36 PM|
|mdrodder58||you can allso use a propain torch like a plumbers just heat the center of the low and cool it quich with a cold wet cloth it will shrink the metal if you do it right and stop the oil can|
|12-12-2012 11:57 PM|
I hope I explained this in a way that's understandable...this may be one of those things where hands on showing would be more helpful.
|12-12-2012 09:44 PM|
|12-12-2012 07:16 AM|
A 28 oz carpenters waffle head is good for building houses, the theory behind a waffle body work hammer was that you could hit with a glancing blow to move metal. I don't use one. I try to keep all my body hammers polished by working them on the back side of my 6 X 48 in. belt sander
|12-12-2012 07:07 AM|
|Chevymon||Do your work only on the weld itself, and don't ever use the waffle face hammer or waffle face dolly for anything, they just damage your metal.|
|12-12-2012 06:14 AM|
|Trophyman||Allow me to jump in with a question. I've been working with scrap body metal trying to gain some kind of feel for welding in patch pannels. When I start the hammer dolly work on the patch, do I concentrate my work mostly on the weld? Is my hammer face smooth or or dimpeled?|
|12-01-2012 01:39 PM|
|Chevymon||Always nice to hear about a good outcome.|
|12-01-2012 12:43 PM|
Glad to hear it.
Thanks for posting the results. Enjoy the pint.
|12-01-2012 12:19 PM|
Thanks to all!
Your tips resulted in success. Now I will be able to sleep tonight. After a 'victory" beer or two.
|12-01-2012 09:08 AM|
I agree with pugsy, do not make any relief cuts or do any work anywhere except on the weld itself. If you are quick enough to planish the weld while it is still hot it will reduce the chance of cracking, but that is history now that its already welded. Do not reheat.
I prefer gas or tig but in the future its important to make sure the patch fits perfect before welding, and with a mig just do a spot here and there and let them cool naturally.
When planishing cold, grind the weld bead almost but not all off the front and back, then put a dolly with a similar contour on the back side and hold it with a good amount of pressure to the weld and strike on the dolly with firm blows up and down the weld area, you should hear the ring of the hammer hitting the dolly. You will see when it starts getting close to the right contour, then start using a straight edge, and keep raising the lowest areas. Its not that difficult, you can do it, good luck.
|12-01-2012 08:37 AM|
I hope it's OK if I jump in here, "123Pugsy" is correct...I will try and explain how things like this happen...when you weld, you create heat, the heat expands the metal, when it cools it shrinks more than it expanded when it was hot. So, when you planish the metal (hammer and dolly) what you are doing is stretching the metal back to it's original thickness. Think of it this way...might sound stupid but it may get the point across...when you tenderize a steak by hitting the meat, the steak gets thinner, but it also gets wider...(sorry but it's the only similarity I could think of at the time). When the metal is back to it's original thickness the warping should be minimalised. Metal has memory, but when it's heated it stretches as it cools it shrinks causing metal to loose it's memory, when you use a hammer and dolly your giving your metal a reminder as to where it used to be.
I hope this helps.
|12-01-2012 07:53 AM|
I was under the impression it was welded twice already and was currently welded.
Do not reheat the area again is you've done it twice already. Planish (cold) along the whole weld and watch your problem area to see if it starts to pop back.
|12-01-2012 06:57 AM|
Does it matter if the weld is hot? I work alone so it's tough to tack it and then hammer. I have read that the weld needs to be glowing. Also, should I tack, hammer, let cool, and repeat? Or hammer when its all welded in?
Thanks for your help.
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