Technical BODY, a patch panel from start to finish

another important tip he gave is to use round corners on the patch panel rather than square corners - the round corners take up less area and thus you are doing less welding - less welding = less heat = less warpage
Very good post!

 

What Tman said about MIG vs. O/A is correct. MIG is very hot and concentrated. It cools fast and thermal shocks the steel, causing the weld to harden too much for sheet metal(if you plan on working the metal after welding). With O/A even though your causing a much larger heat effect zone, it cools slower and remains softer. It will grind easier, and most important, can be worked with hammer and dolly with out cracking.

More on hammer welding. You want to hammer the weld as fast as you can. The hotter the metal the easier it stretches, and the less it work hardens. You use "hammer on dolly". The weld is sandwiched between the hammer and dolly so that it is forced to thin, which increases the surface area.
You are trying to compensate for the shrinking that happens when the metal cools. How close you match the stretch to the shrink will dictate how close the metal will be to it's intended shape when your done.

BTW, I use 1/16" mild steel rod for most work, once in a while I'll use 1/8" if I have a wide gap to fill.

 

Very nice work ,I have a set of o/a bottles ,have not used them in years. The price of gas over here is wild . Seeing this I will have to get them filled..

 

For all you guys wnating more info on that Henrob torch setup, there's some great how to info on their website - I couldn't pull myself away. I found it a couple of days ago and had to "work late"

lounge

http://www.cut-like-plasma.com/

 

bttt

 

I will bttt this one!

TECH-O-MATIC!!!!TECH-O-MATIC!!!!TECH-O-MATIC!!!!TECH-O-MATIC!!!!TECH-O-MATIC!!!!TECH-O-MATIC!!!!TECH-O-MATIC!!!!TECH-O-MATIC!!!!TECH-O-MATIC!!!!TECH-O-MATIC!!!!TECH-O-MATIC!!!!TECH-O-MATIC!!!!TECH-O-MATIC!!!!

Mike

 

Tinbender, have you ever tried the Mecco Midget and compared it to the Henrob?

 

Tech-O-Matic! BTTT

Already in my favorites

 

Here's some more thoughts on patching....After I weld in a patch, I turn off the shop lights, and hold a spotlight behind the panel to check for pinholes. I also prefer to use a very thin coat of "all metal", front and back, before finishing with bondo. I used to lead the repaired area for insurance, but now feel that we have some modern alternatives that are less of a health issue. One other thing....when you are repairing a "sandwiched" area, weld-thru primer is a good idea...available either as a spray or brush on application. Some of these ideas are from ICAR training on unibody...good course if you ever get a chance.

 

Top Tech!!!

 

Great tech, very well organized and informative!

 

Thanks for the nice words guys!
Banzai, nevr tried the Mecco, but I've heard nothing but good about it.

Hatch good tip on the light, I check my welds all the time with a strong flash light. As for the All Metal, I don't use it, and I strongly recommend against it. It's unnessary and prone to cracking and leaveing ghost lines, all the things you avoid by gas welding.

 

I agree on "all metal" cracking. No flexibility at all. I only use it over the weld and almost thin enough to see through. The one advantage is moisture can't get through it, where with bondo will absorb moisture.....Great post and pics...hatch

 

I just went to to the sight, AWSOME!!! Its a "MIRACLE TORCH"! I gotta have one when i save up my pennies. Thanks for a very cool tech! Iv been doing bodywork and patch panels for years!, but i certainly learned a thing or two off this post. Thanks