Cutting Stainless Steel Firewall

[MotReklaw]

I'm looking for a better way to trim my firewall than the traditional Wiss tin snips. I don't like the way the metal deforms and looks wrinkled.

Anyone have a better way than won't put me in the poorhouse?

Thanks

[Dave S]

Tommy,

If a person has a band saw, getting a very fine tooth metal cutting blade for it works and the blade doesn't cost that much. If you are cutting around the edges of a panel the throat depth of the saw is not usually a problem; but, a person is limited by the saw throat if needing to cut into the middle of a panel. Finishing off the burr edge of a band saw cut with a file leaves a nice edge and no deformation.

I ended up using the band saw a lot on our kitfox project - for aluminum mostly.

Other options are a sheet metal nibbler (which has some cost to it); or, a smaller diameter high speed abrasive wheel - which needs a high speed grinder of some type to put it in.

Sincerely,

Dave S

[HighWing]

Tommy,
I finally replaced my left cutting (red handled) aviation snips. I did so because of the distorted edges and sometimes even a rolled edge with no cut. I would recommend first going to Lowes and getting a new snip - that is where I found mine. My new ones cut clean and neat - about $15. I do agree that the rolled edge so common is not very sightly.

A question for dave. Do you have a multi speed band saw. The reason I ask is that Stainless hardens quite rabidly when heated. This is the reason a very slow speed is best for drilling through the firewall.
Lowell

[MotReklaw]

I have a bandsaw and a new metal cutting blade still in the pkg. I may give that a try on a corner of the upper firewall panel. I also have a friend who bought a new nibbler while he was rebuilding a Cessna 140 and I may ask to borrow it, hate to be a borrower though.
Lowell, These snips have been through several aircraft, most often cutting alum. I go by Lowes every day so I might stop in and see what they got. I know some of the new snips don't have the serrated edge and that might solve my problem, if I'm willing to throw money at it.

Thanks for the tips. appreciate it.

[chefwarthog]

You can use a grinder with a ''ZIPCUT'' disc for stainless, it is a very thin but very effective way to cut metal in non time, and it don't discolor the edge! (stainless one)

http://www.youtube.com/watch?v=KtsgI...105317&index=5

[jamesmil]

just a tip on using snips on any metal,dont squeeze all the way to the end on each stroke as the very end of the snips will deform the metal. stop your cut at about half stroke.

[Dave S]

Lowell,

The bandsaw I have is operating at a slow speed - it's not a two speed - just set up with a pulley speed reduction drive.

You are correct - a slow feed and slow blade speed is important to prevent any heat buildup.

Dave s

[DanB]

I know you said you wanted to keep the price down and to be honest I cant remember how much the Rodman nibbler cost, however, I have used it a bunch since I picked it up at OshKosh a few years ago. I don't think the price was too bad and the cuts made keep your project from deforming. It went through my stainless firewall like butter...Worth looking into.

http://www.azshowersolutions.com/Shop7.html

[jrevens]

One little trick I learned in building a metal airplane is to use a large pair of smooth-jawed shears when possible, and cut very close to, but not right on your scribed or marked cut line. Then make your final cut trimming off the very thin edge of material that is left. This results in a smoother cut with less distortion, As previously stated, don't cut right to the end of the shears - stop before getting there & carefully reposition them to continue the cut. Finish with a file, etc. It's nice to have a variety of nibblers & cutting tools.

[MotReklaw]

Thanks for all the help guys. One of my airport buddies loaned me two tools to get the job done. A B&D Industrial nibbler and a Kett Power Shear. I liked the shear best on the long areas. The nibbler was better on curves.
Here's a picture of the tools.