Let's start by saying this engineer disagrees.Yes.
Although for the cost of O2 and acetylene gas on a project the size of a cub fuselage, you'll be halfway to paying for a reasonably nice TIG welder by the time you are done.
If you are even a marginally capable gas welder, TIG is a breeze.
Yes, .. that being my guess, as well. I've messed around with TIG, .. but, never with OA.Gentle? you are talking about welding here. I once worked for an engineer very experienced in fabricated assemblies. "Welding f**** everything up."
TIG is not as hard on the steel, less total heat in the assembly, less distortion during and after the weld, less oxide scale, but it is welding - you have a puddle of steel at more than 2600F, and everything around it expands with the heat, and then has to contract afterwards.
Most homebuilt and certified aircraft are designed and built without post heat treatment. It is not necessary to oven heat treat a fuselage after completing and is not cost effective. Also any oven heat treated parts will require another heat treatment cycle if repaired after entering into service. Most of the certified steel tube fuselages were never oven heat treated, although some of the landing gear parts on some light aircraft were (Luscombe).Recommend go to University library that has an engineering college. Find a book on aerospace by Brum. Then look up Society of Aerospace Engineers Welding Standard for 4130 and post weld heat treatment. There are several commercial heat treaters in the market place. Google for one's in your area. They have ovens and Good controls. They will want you to specify the heat treat recipie. Good luck. I've supervised welding & PWHT of 4130 for Ocean going ship parts, turrets, and superstructure.
I'm not a welding expert by any standards, i read on various forum that using Oxy-Acetyl for fuslage was the only recomanded way to go as it has (supposedly) stronger welds and remove the need of any pre/post heat treatment to avoid cracks and tensions.I still gotta ask why the OP is tacking with stick but not planning to do the welds with stick? Seems like the natural progression to me, and the above experts say so too.
Tacking with a stick is faster, easyer, and more economical, also i wont have to heat the area i need to weld multiple times and possibly end up making it weak.If you are welding with oa anyway what is the problem with tacking with it?You should have some form of jigging to hod the parts and that should be adequate to hold it enough for tacking.Another too I use for exhaust pipe work is aluminium tape. You wrap your joints and lift enough tape to get a tack on.