South Jersey Skybolt :: A Radial Engined Biplane

Aircraft Welding 101.1:

June 8, 2007
four months to go... sheeeeeeet

Howard told me that he practiced 8 months before he started tack welding his fuselage. I was thinking... sheeeeeet, that's a mighty long time to practice welding. Sheeeeeet, he wasn't kidding. I've been pushing the puddle for a little over four months now; off and on practice, but practicing just the same. At this point I wouldn't feel confident about welding up an airframe and having sound welds.

I hope to have some time to practice this weekend. I'm looking forward to being able to weld a few nice clusters.... as a matter of fact I can't wait to show off those clusters to the guys at the EAA Chapter.

I'd like to get started on the fuselage in August some time. Hopefully have it all welded up by the end of September, maybe by the end of August if I put some long days on it.

June 11, 2007
riding the beast...

Back out to the workshop... working on those welding skills. Whether a fluke or getting the hang of it, I felt like I was holding my own... staying in the saddle tonight.

In the beginning of tonight's session I was adjusting the flame length a lot. I finally got it close to what it was suppose to be... only popping every once in awhile. I'm getting the hang of following the curve of the tubing around it's arc. Getting to the point where I'm standing up and welding, without having to steady either arm by resting it on my leg or some other item.

Although sloppy, I'm pushing the puddle around these round pieces of thin-walled tubing like they were two flat pieces of metal. I was in a groove tonight. Not sure if it was the groove but a groove none the less.

I've said it before but it bears repeating. The heat to push that puddle while I was practicing in the begining... is a little bit different than the heat you need to weld two pieces of flatstock together.... which is different than the heat to weld thin-walled to thin-walled at 90° or any one of various angles. To get, and keep, that puddle moving at a nice clip you need to adjust that flame up or down. Heat has a direct affect on puddle flow which affects the application of the rod to the puddle which all comes down to a good or bad weld joint. (I couldn't leave before I extolled you with a little bit of wisdom)

OK... back to the moment. Only time will tell if I'm getting the hang of fusing metal to metal; if I'll master riding this beast.

June 13, 2007
dual puddles... staying in control...

Another round of practicing. The flame was right and the puddle flowed. I took the torch down to the smaller tip. Amazingly the popping stopped. (actually... nothing is amazing, it's all a matter of understanding... well, it is amazing but, ahhhh, you know what I mean) I'm doing something right.

The length of the flame was about 3/8ths of an inch which worked out to be the right length for the thickness tubing I was welding up. After preheating the surrounding area everythng worked together to produce a nice environment for welding. Not that I had perfect welds, but that's just a matter of feeding the rod into the puddle at the right angle and speed. A matter of more time, aka practice.

I ran out of practice tubing again but had enough unfinished weld joints, from previous sessions, to keep me busy for a little over an hour.

I'm not sure if I've mentioned this in any previous entries... I found that keeping the dual weld puddles going, for the two pieces of tubing, requires that you "play" the flame back and forth over the two pieces. You just can't hold that flame down the center of the two pieces, in the "V", and expect to get both pieces hot enough to flow. A flame that could do that would burn holes in them quicker than you'd think.

Playing the flame back and forth requires a little bit different approach to feeding the rod into it to keep it happy. Nothing difficult, just a different approach, a modification to what you have already been doing.

With practice I'm finding that I am able to weld at different angles. It's always best to position yourself for an easy weld but that ain't gonna always be the case. Never continue the weld if it starts to get out of control, when you're unable to manage playing the flame and feeding the rod. At that point stop, spin whatever you are working on, or reposition yourself. Do something to regain control. Be in control at all times. When you're out of control your weld joint will most likely be unacceptable. Not good in an airplane.

Understanding a little bit more each time I have a go at it. I'm hoping to build on this tomorrow night.

June 18, 2007
still adjusting to it all...

Adjust adjust then adjust again....
get that flame at the right setting.
If the puddle ain't workin'... the flame needs re-adjusting.

The quicker you get the correct setting, the quicker you'll get nice weld lines. Fart around with an unacceptable flame and you'll get nothing but unacceptable welds.

Tonight's session... the first half of the night I was getting lousy welds. (guess I was farting around with an unacceptable flame, eh ?) The second half of the night I made those lousy welds look nice... at least the remaining part of them.

Another part of the misunderstanding chipped away.

August 29, 2007
Fannel Shirt, Blue Jeans and Boots...
Hell no... it's not winter
Just getting ready to do some welding

Yeah, it's been awhile since I last lit up the torch. Felt good to be pushing that puddle around again.

I had cut and filed quite a few pieces of tubing awhile ago so that I could practice at a moments notice. That moment came and went... for the life of me I couldn't find that tubing. Probably took the better part of a half hour before I found it. Kinda put me behind the eight ball with my plans for tonight. I wanted to get in a good bit of welding since it's been so long since last practicing.

With this mind set, I was a little impaitent, I wanted to pre-heat that tubing fast and get to work with my weld lines. WRONG ! No matter how fast you want to get to welding... you just can't rush things. You'll either be turning that flame up too high to get a good weld, snap-craklin-and-popping, or you'll be dipping the rod in before the puddle is ready and you'll be sticking it to your work more than running the puddle. Neither of these are very productive to practicing.

Luckily I had the sense to realize this before I got too far into tonights practice. I completed three welds tonight. Not as many as I had wanted to, but that's not what this practicing is all about. I made three welds. The first actually not that bad considering the gap in practicing... the second one much better and the third a damn nice weld (still taking into account the 2 1/2 month hiatus.)

Looks like I was able to climb back up on that bull without forgetting too much. YeeeHaaaaw !

September 4, 2007
as the puddle flows...

When you get that puddle going, it wants to go on it's own. All you need to do is add some of that weld rod to keep it happy.

It seems to me that you need to work at getting a bad weld line. When the planets align, and all is going right, that puddle has a mind of it's own as it creeps forward. All you need to do is point it in the right direction. At times I can't feed it fast enough.

Spent about an hour practicing tonight. A little rough getting started. Not too bad though. I'm actually close to where I wanted to be, when I first picked up the torch several months ago, but now that I'm here, I'm not where I want to be. Follow that ? The better I get the better I want to get. By the end of the month I think I'll start to weld up my rudder pedals. Practice on the small stuff. That way if I foul things up, I haven't spent that much time or money on it.

Take this away with you tonight... to get better welds it's ideal if you have something that will hold your pieces where they need to be, at an angle they need to be. Don't be like me and lean the tubing up against something to hold it there. Never really works. Or it does work, works against you that is.

In addition to that great piece of information... I'm finding that the popping and blowouts I get from the torch is based more on how I have the torch held to the piece than the length of the flame tip. Although, the flame tip has some bearing on it. I find that if I have a longer tip and face the torch more directly at the tubing, it has that tendency to allow the gas to ignite inside of the tip. It as if it's hitting the tubing and blowing back into the tip.

This idea goes against what I've been told. It's my own observation over a period of time. Take it for what it's worth. And with that, I'm calling it a night.

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