Jim's XL build D-25

[Jlwright]

I am officially an XL builder as of today.

[hvacrbert]

good luck! I figure i will be about 3 weeks behind u I will be watching.          bert

[Sam Buchanan]

I am officially an XL builder as of today.

Yes, Jim, you are indeed an Eagler! 

However, I am a bit concerned about your shop----it appears you don't have much in the way of equipment, it looks like you have only the bare-bone essentials, hope you are able to make this project happen with the tiny little accommodations you are forced to work in......  

[Jlwright]

Hey Sam. Yes I am truly gullible. How do you like my table setup. :-)

[Jlwright]

Made some progress today. Tacked in the cross braces and diagonals. The Mecco torch is the bomb. Thanks Sam.

[Jlwright]

Decided to try my luck at finish welding a sample similar to some of the fuselage welds. I do tig welding as part of my job but have never welded with a gas rig before. I have no doubt this weld is strong but I am used to doing precision work and gorilla welds are certainly not what I want all over my fuselage. This will be the biggest challenge of the whole project for me. I really love learning a new skill set. My father was a master welder using  a acetylene torch. He learned the trade in the Navy and he thought nothing of brazing a huge cast iron casting back together. I've seen him weld a part so large that there were two helpers preheating with rosebud torches while he brazed. That one part took nearly 8 hours to finish. I was never interested in learning that aspect of welding when I was growing up as I thought it old fashioned and would be replaced with newer techniques. Now I can just kick myself for not learning while I had the chance. Dad never pushed the issue either. I think he wanted me to learn new skills that were not so much of a health hazard. Here are a couple of pictures of the before and after.

[scottiniowa]

but I am used to doing precision work and gorilla welds are certainly not what I want all over my fuselage.

While not tig welds, those welds are far from looking bad, in fact I would say well done for a few first try's at welding. And almost without out a doubt stronger than tig weld, and the tig welded clusters are plenty strong.


Scott -  

[grdev]

Nice work1
Gil

[Jlwright]

Thanks for the encouragement. I am using a Mecco mini torch with a #1 tip. It seems to be a little small especially when welding the crotch areas. I have to go real slow in order to keep the heat up where it needs to be to get good penetration.

[Sam Buchanan]

Thanks for the encouragement. I am using a Mecco mini torch with a #1 tip. It seems to be a little small especially when welding the crotch areas. I have to go real slow in order to keep the heat up where it needs to be to get good penetration.

Jim, I started out as a complete novice at gas welding and had read a bunch about having a "quiet flame". I quickly found out when welding clusters I needed to turn up the gas until the little torch was roaring like a blow-torch (well...maybe not that much...). Don't hesitate to crank up the juice in order to get the heat you need. At first I couldn't control the torch enough to use a #2 tip but I think my #1 has now worn enough to where it is about a #2.

[rockiedog2]

on the big clusters i go to a Smith #5 that way we get plenty of heat and the quiet flame that Sam is talking about. on the smaller stuff I use a #3. i dunno what a Smith #5 would be in a Meco

[Jlwright]

I have a #2 and #3 tip for the Mecco. I'll do some more experimenting. The quiet flame on a #1 tip just doesn't put out a lot of heat. It sure is nice working around those thin edges though. It would be nice if everyone used the same numbering size for their tips. A number whatever hole should be the same no matter what the brand.

[Dan_]

I have a #2 and #3 tip for the Mecco. I'll do some more experimenting. The quiet flame on a #1 tip just doesn't put out a lot of heat. Ibrand.

Here is how to decide when to go up or down in tip size...  When you start building up a cluster you wind up with a lot bigger heat sink and may need a bigger tip...

I dint invent this, just passing it along.

With both bottles on, and regulator adjusting screws turned out (“off” position), turn the acetylene (Mecco) torch valve wide-open (3 half turns is usually enough).  Then, turn your acetylene regulator adjusting screw in until gas starts to flow and light the torch.  Continue to turn the adjusting screw in until the flame just blows away from the tip, then back off the screw until the flame just returns to the tip.  Your acetylene pressure is now set for that tip.
 
 Then , open the oxygen (Mecco) torch valve wide-open (3 half turns) and slowly begin to turn your oxygen regulator adjusting screw in until you you have a blue feather extending from a blue cone at the tip.  Continue to add oxygen until the feather just disappears into the inner cone, giving you a neutral flame.  You now have the torch set for maximum heat for that tip.  (Wiggle both torch valves at this point to make sure you have them wide-open: if you do the flame will not change)
 
 Finally, turn your oxygen torch valve off. Then, close your acetylene torch valve until the yellow flame starts to produce smoke, and immediately open it just so it is not smoking. Slowly open your oxygen torch valve until you again have a neutral flame , and you now have the minimum flame you can use on that tip without backfires.
 
 This seems like a lot of trouble, but only takes a minute with practice and only needs to be done once unless tips or regulator settings are changed.  Also, note that at no point are you depending on or even looking at regulator gauges, which can be very unreliable when abused.  This method will work with all standard OA equipment for welding, and is called "balancing the gases".
 



Sorry it is not a regulator setting video, but you can see the nice blur on the inner cone here...

[Jlwright]

Thanks Dan for the information. I was doing it sort of right. I was using the regulators to set the torch but was turning on the acetylene until I got a feathering flame and not until the flame left the end of the tip. Thanks for your help.

[Jlwright]

A little more progress. I decided to try bending the top longeron on the concrete floor and then adding it to the fuselage. I shot the laser through the hole in the box fixture to line up the top longeron with the tail post and the top. The little Ryobi laser is a great tool for this kind of thing. My line on the table lines up with the laser light and centered in the fuselage. It throws a horizontal line as well that you can raise or lower using a camera tripod. The laser also puts a line on the center of the sloped part of the top longeron to make it easy to keep plumb when adding the upright tubes. BTW,Bending the longeron was not my bright idea. Again, Thanks Sam it worked great.