Jorge,

The other guys who have answered your query are really knowlegable about this issue and the particular model so I am not going there.....I'd like to offere some comments on welding methods since that hasn't been touched on very much.

True, the original construction is all electrically welded; but, that does not mean you can't or shouldn't have the repair done with gas welding if it is available or the only option. Electric welding is common because it is fast and economical. Gas welding (by this I mean Oxy-acetylene welding) is entirely compatible with 4130 steel as used in aircraft frames (and the Kitfox) for a really long time. Many of the Classic tube and fabric planes are entirely welded up with gas. Gas welding does cost more in time and materials. It is a method that is also extremely versatile; and, requires a degree of skills not everyone is familiar with (except for those who do it). Aircraft gas welding often utilizes a process called "normalizing" - using the torch to heat up the completed weld and allow it to cool gradually to relieve stresses - hard to do without a flame.

One big deal - you use 4130 gas rod for welding 4130 steel - do not use mild steel rod. A competent gas welder knows this and how to get ahold of the right filler rod. If a welder doesn't understand this - walk away fast. Such filler rods are normally stamped on the end of rod with the 4130 identity - much like other specialty rods used for gas welding.

I will say that welding 4130 materials with a gas torch is one of those processes that work very well...the melt pool flows so well and flows together so well it's almost hard to believe something could work so well.

If you have a competent operator who does gas welding - no reason to rule that out. You can certainly do either gas or electric.

Sincerely,

Dave S
KF 7 Trigear