|04-15-2003 08:51 PM|
|kiaserknife||when I use a butt-weld I lay up the old panel and cut thru both at the same time using .040 cut-off wheels three to four inches in diameter any wheel thicker than that and your looking for trouble getting the gap to shrink. harbour freight has clamps made for butt-welding that hold the panels precicely .040 apart...a butt-weld is a strong weld, the problem of cracking comes from a number of conditions...such as wire used...most wire feed wire used in shops is of higher strenght than the mild steel of your panel. higher strength realates to less flexibility...after repeated vibrations, such as years of road use can cause cracks, tho not common it does happen, also the pocess of grinding the welds causes the welds to be hardend as if it was heat treated..easy cures include grinding the weld in the same manner in which you applied them a little at a time..also when doing panels use wire known as easy-grind wire .023 its harder to find and cost considerably more than ordinary wire but the time saved grinding is well worth it.|
|04-15-2003 04:10 PM|
|adtkart||Unstable... the point that I was trying to get across is that by cutting the patch panel large enough to use lap joints, which is a stronger repair, you will not have the problems of trying to fill gaps when the patch is smaller than the hole you are trying to patch. I don't mean to put you down for asking the question, but quite frankly, if you knew what you were doing you wouldn't be asking. For someone that is experienced in this, a butt weld may work, although not as strong. For someone that is starting out, besides being a stronger joint, the lap joint allows some room for error. Even those of us that have been doing this type of thing for some time need that from time to time. Since there is no place on a car that sheetmetal is butt welded from the factory, that should give you some idea where I am coming from. If the factory could cut 1"-2" of metal from every joint by using butt joints without loosing the strength, don't you think they would? Think of how much they would save in a year. Food for thought. Do it however you want. It is your project. I just wanted you to have the information available in case you wanted it. When I started out the only way to learn was from the people around youor if lucky, from magazines. Usually the photos were useless, as were the directions. Good Luck.|
|04-15-2003 01:50 PM|
I butt welded everything on this project. Used MIG w/ .027 solid wire CO2/argon gas. Just did quick spot welds - 1" the 1/2", then 1/4" etc. spacing 'til it was welded solid. No heat distortion whatsoever.
[ April 15, 2003: Message edited by: firstname.lastname@example.org ]</p>
|04-15-2003 12:59 PM|
I'm just going off what I read in the article. If you get a chance, go to <a href="http://www.brotherstrucks.com" target="_blank">http://www.brotherstrucks.com</a> and look under "tech articles" for the 55-59 door patch panel.
I agree with you on the 3/8th statement of the blade...that is very true. But I don't understand the other point you are trying to get across.
Again, I come here to get good input on stuff, people who have actually done this before would know better than little old me...the guy who reads articles. This article just seems to make sense. You could zig-zag through both panels and in the end you should still have a match.
|04-14-2003 05:21 PM|
|adtkart||How are yuou planning on cutting? You have to figure for the thickness of the cutting tool. Let's say you are using a 1/8" saw blade. That means that the patch piece will be 1/8" smaller than the hole, all the way around. That will make a weak butt joint even weaker. You cannot cut a hole and the patch panel at the same time, by placing the patch piece over it, and have them the same size.|
|04-14-2003 05:48 AM|
To the best of my understanding, if you use the method they show on the brothers-trucks site, you shouldn't have any need to trim.
Procedure is as follows:
++Mock the patch panel on the existing metal, making a mental note of where the rusted-out areas are.
++Cut through both the patch panel, and the original sheet-metal (which is rusted).
++You are left with two "loose" pieces of metal.
1-the old rusted crap
2-the new patch panel
Both should match precisely
++clamp the new panel in place and weld.
You guys would know better than me, as this is going to be my first attempt (after I practice a little of course). But the logic involved seems to make more sense to me than what you guys are proposing...I just wanted to get the "experience" factor involved in this mix.
|04-13-2003 04:49 PM|
|adtkart||I probably wouldn't butt weld a very large patch panel in a door, as I would use a lap joint. If you really want to patch it that way, make sure that you don't cut the patch panel too small. Trim, and trim, and trim until you get it as close as possible to the size. Mig welding is the only way to go for the average person at home. I understand that some may have TIG set-ups, but most don't, and it is harder to control the heat to prevent warping. Also weld only short areas at a time, allowing the metal to cool. That will reduce the chance of warping.|
|04-13-2003 10:24 AM|
Hopefully this link works.
<a href="http://www.brotherstrucks.com/techarticles.shtml" target="_blank">http://www.brotherstrucks.com/techarticles.shtml</a>
55-59 Lower Door patch panel installation.
My buddy who is a wood worker suggested using a circular saw. He said that they make blades that will cut through mild steel. Just wondering if this is feasible...I do have a cut-off tool, but even making the smallest cuts I seem to be all over the place...might have something to do with how much coffee I drink, can't keep a steady hand to save my life.
|04-13-2003 02:22 AM|
The panel that is going to be put on is normally larger than need be. Mark it out to the size that you need to cover the area that you are going to repair. Trim this new panel straight using either a GOOD set of snips or preferably a set of electric shears. After trimming it to satisfaction, lay this panel over the panel you intend to replace and mark the old panel. Cut the old panel out leaving 1/2" to 1" of extra material. After cutting out the old lay the new up and make sure you still have some material to trim. Start trimming down until you are satisfied with both panels fitting with a butt joint. Another way that some do it is to purchase a flanging tool to flange the original panel and lay the new into it. It will only flange enough to make both panels flush when put together. Usually you can pick one of these flanging tools up at the local swap meets at almost any tool vendor. One side of the tool flanges while the other side pierces a hole. With this you have a hole to spot weld thru. Then finish as with your desired coatings and fillers.
|04-12-2003 10:34 PM|
I use a MIG, Hobart Handler 175 at home for basic bodywork and repair. For motorcycle tanks and other goodies that will need to be leak and flaw proof I use a TIG at work. I don't normally use gas anything because I'm a person thats keeps it simple, to much going on and I don't know if I'm coming or going. I'm learning slowly to use the TIG for frames and other structural things. I'm new to structural welding, usually my late bro did it for frames and etc. Sheet metal and repairs are easy.
I moved last week tuesday, love it here. Had a waiting list a few thousand years long. I had to give a few people CPR and adrenalin shots to get bumped up the list.
|04-12-2003 10:22 PM|
Hey HK, what do you use for welding a patch pannel in? Do you prefer MIG or gas welding or something else? Oh ya, when did you move? :p
|04-12-2003 07:34 PM|
Your never going to get a panel cut perfectly straight unless you do it on a ban saw with a guide. The only way to cut your door reletively straight is by using some sort of guide to steady the blade if your using some sort of saw. Easiest way would be a plasma cutter, but who has one of these unless they are a metal worker.
You don't need to cut both panels on top of each other, sure it would probably work, but be a pain in the ars. Just cut out the rust and after you clean the edge and straighten it out with a file if need be. Then just place the peice of sheet metal you plan to cut the patch panel from on the outside of the hole and from the inside out use a rattle can of anything and spray the edge. The sheet metal will have the identicle shape of the hole needing to be patched. Just cut it out and weld it in.
|04-12-2003 06:26 PM|
Patch panels and cutting?
I've read a few articles that said the best way to install a patch panel is to clamp the new panel OVER the existing panel and cut through BOTH pieces of metal..this will give you an exact fit in which you can BUTT the new metal against the old (after removing the rusted stuff you just cut out.
Question of the day is...what's the best way of cutting STRAIGHT? I guess at the end of the day it doesn't matter, if both pieces match up perfectly...but I'd much rather cut straight than zig zag across my door.
Any tips on this?