Advice on a light-duty O/A torch?

admin

Hiya folks,Absolute beginner here, hoping to buy a light duty O/A setup for welding up boat parts... mostly thin aluminum, up to about 1/2" stainless, and up to around the same in silicon bronze.  So far, I've been leaning towards the "aircraft" style torches... thinking along the lines of a Smith AW1A or Harris 15.  I've also eyed the (more expensive) Harris with the auto shutoff/pilot light feature.Anyone used this type of small setup for things like this?For instruction, I'm planning on picking up Geary's book (many reviews say it's the best for O/A), and possibly/probably taking a class at the local tech school.  They have a class specifically on O/A.And, of course, reading the forums. Thanks!Jason
Reply:I'm saving up for one of these:http://www.cut-like-plasma.com/
Reply:I've read a lot of reviews/comparisons about the Dillon/Henrob torches... at first I was pretty stoked about the idea of it, but the more I read, the less I was interested.  A lot of people complain that the Henrob is quite heavy, especially when compared with the lightweight aircraft style torches.  I do really like the idea of the soft flame, but I think that's also a function of gas pressure and tip size, and that if you use a small torch, you'll have that type of flame anyway.I guess if they were to make a torch that used that same mixing process (is that what's so "special" about the Henrob design?) in a more traditional shape and weight, it would be a real winner.For anyone who actually knows what they're talking about, please correct me!
Reply:I think you have the right idea with the Smith AW1A or a Harris 15. The "Auto" torches are nice for production work, but more maintanence with the extra valving, seals, etc. The Dillon design torch has a nice flame, but nothing better then a GOOD standard torch tip flame, and yes its very heavy and expensive. Both Smith and Harris make fine tips, Im partial to the Smith since its still made in the USA, but the Harris quality is equal. If you go the Harris route look up the 1390 series tips and D-50 series mixing tubes, they are the production type that has been in current use since the 1930's and are superb. If you havent seen the picture in the oxy-acetylene thread of my collection, im not kidding when I say ive tried almost every torch made in this size range  If it wasnt for your desire to do heavier work, I would also suggest the Meco Midget for sheet work.
Reply:Thanks Mako,I've been leaning towards the Smith just because it's easier for me to find them, but knowing they're still made Stateside is a definite plus.I've also checked out the Meco, but the ability of the Smith to cut, and the heavier stock welding capability made me lean that way.Thanks!
Reply:Sounds like a plan! Pair it up with a set of the new Smith medium duty regulators and the kevlar brazing hoses they sell, you wont be disappointed. You may want larger hoses for cutting though.
Reply:i just bought a boston industrial med duty torch kit for 85buks
Reply:Originally Posted by makoman1860Sounds like a plan! Pair it up with a set of the new Smith medium duty regulators and the kevlar brazing hoses they sell, you wont be disappointed. You may want larger hoses for cutting though.
Reply:Your planning on welding 1/2" stainless with oxy/acy?  I know stainless can be done, ive done it before with some success.  However, is this really a good choice for thick stainless?Have we all gone mad?
Reply:Originally Posted by sn0border88Your planning on welding 1/2" stainless with oxy/acy?  I know stainless can be done, ive done it before with some success.  However, is this really a good choice for thick stainless?
Reply:For repair, I guess you might be able to make due in a pinch but its not going to be pretty.  If your planning on building something at a shop/garage/workspace of some sort then avoid oxy/acy for stainless if at all possible.  Cheap stick welder might be your next best option.Have we all gone mad?
Reply:You're going to have problems with carbides if you do stainless with the O/A.  You will need to use some method to passivate the stainless after welding or it will corrode around the weld area.
Reply:Provided you use the right technique, fluxes and filler you shouldnt need to passivate most common stainless alloys. Remember all the exhaust systems built in WW2 from stainless and inconel....all torch welded....and few were passivated. I have seen NOS systems on a Wright engine, in the as-welded condition. I aggree though that 1/2" plate would be a tough job, but 1/2" round stock or smaller fittings shouldnt be a problem at all.
Reply:From what I remember, they used to passivate stainless by boiling it in nitric acid.  I'll just get a jug of it and do that on my stove.  Should work for small items, right?  Seriously, I imagine there's a place that does that somewhere in Calgary... but starting off I'm probably going to be working mostly with the Silicon Bronze.  The very tentative plan is to design what I want using Sketchup or Solidworks, then make a model from mild steel, try it out, then make a final version from bronze once I get it like I want.