fuselage part 2

[dedgemon]

Since I'm now in the welding phase of the fuse I thought I would start a new thread for it. Warning: I'll probably show pictures of welds in public. Y ou would think I'd be smarter than that. 😊

Biggest problem so far is fitting my head and hood into the small frame openings at the back of the fuse. I've got the tail post area and frame H welded. Not especially pretty but Done.

[sjt]

Do you have a recommendation on primer for your 4130 stuff? I have an epoxy primer ep420 that I use for aluminum, but mixing it up for each and every 4130 part makes priming inconvenient.

In an ideal world I could get something and avoid hazardous material handling charges.

[dedgemon]

I've shot PPG coatings on my other planes. Their best epoxy primer is DP and it is excellent. I've also had very good luck with their OMNI and shopline epoxies. I think any of the good grade epoxy primers will work just fne. The bigger issue is the prep and application. I have'nt found anything thats easy that really works. Unfortunately the only good anti-corrosives are catalized so you have to mix and spray and clean. I just try to do as much as possible at once.

[geraldmorrissey]

I'm not there yet but as far as I'm concerned you can't publish enough photo's Great reference material. More please. Do you have a build log?
Thanks
Gerry
Patrol #30 Wings

[dedgemon]

No builders log Gerald. I keep it very simple with a handwritten logbook to satisfy the DAR and a bunch of pictures. I'll try to put as much in here as you guys can stand. Since we're a small group I figure this is as good as any other way to document things.

This is being a slow build for me since its mostly from plans and I have a 12 year that gets more of my time than the shop does. That'll change soon enough.

[alaskabearhawk]

This is the best thing I have found when going into tight corners...just wish I had found them sooner. World's first auto-darkening welding goggles. I had a local optical shop make cheaters for them. They are well worth the money and then some. Servore manufactures the Miller version:

http://store.cyberweld.com/miwe26.html

http://www.amazon.com/Servore-Darkening-Welding-Goggle-Arc-513/dp/B00LKWLSS0

[Chris In Milwaukee]

Wow, those are great!

[dedgemon]

Paul, I looked at those a whilr back. Now that I've spent the weekend trying to fit my hood into places it just cant go, I'm sold on the idea.

How is the image, pretty clear?

[alaskabearhawk]

The image is great. Another benefit is there is no glare or reflections on the inside surface like using a welding helmet. The +2.00 cheaters were expensive ($125.00) to have them made to fit the frames provided with the goggles. I guess I could have done with a set of cheapies and fit them myself. But the local eyewear place made them out of superior optical-grade plastic using my prescription to fine-tune for each eye. They also put an anti-scratch coating on them and for the money they are guaranteed for life, no questions asked replacement if they ever get too scratched or damaged...and that will happen eventually.

[dedgemon]

Well I ordeded a set of the googles that we were discussing above. When the local optical place wanted a Rx for the cheaters I bailed. I went by the drug store and bought the same pair of cheaters I use under my normal helmet. I cut off the temples and they fit great inside. Put a little sliver of aluminum tab in there to hold them in place , but I'm not sure its even needed. These things are small and look like a great solution for the inside welding.

[alaskabearhawk]

Funny, I just got through using them and letting the weld cool when I saw your post. I never have used the hood though. I just use a weldor's cap for my noggin' that is exposed above the goggles.

[dedgemon]

Back in the shop today to do some welding. The goggles work great, very easy to get into position to see the interior of the cluster. The image is not bad, but I'm spoiled with my Jackson Trusight. Thats the best auto darkening lens I've seen, big bright clear image. The main thing is to be able to get to the right spot so that you can see and have a comfortable prop for your hands.

Did a few welds, starting to get a little better. (but my amateur standards at least)

[Bdflies]

When the first 'quick change' helmet lenses came out, I never expected them to sell. We sold inexpensive helmets (complete with lenses) for less than $15.00 and the new fangled qick change ones were about $350.00, in the late 80's or early 90's! Well, I was wrong and the helmets sold and the breed has improved. I've been away from that market for a while and haven't used the Jackson version that Dave mentioned. The hands down best I ever saw (and still use) is the Hornell Speedglass. The product line was sold to 3M, but is still marketed as the Speedglass line.
If any of you are looking to buy such a helmet, for welding on, in and around a bunch of tubing, keep in mind a couple of factors:
1) be sure to get a lens that offers adjustable darkness and sensitivity.
2) Be sure to get one with multiple light sensors. The cheap lenses have a single sensor. You can easily wedge your head into a position that allows you to see the arc, but if the single sensor is shadowed by a tube, the lens won't go dark. Surprise! Or worse, it goes in and out, as you move, while welding...

Nice welding Dave! Are you using a gas lens on your TIG 'torch'? The gas lens changes the turbulent flow, in the nozzle, to laminar flow. This allows you to extend the tungsten much farther out, without losing argon coverage. This really helps get into the tight joints! If you've never used one, it'll change your life. Not really, but you'll be surprised.

Bill

[dedgemon]

Bill,
I'm using a #7 size gas lens with a pyrex cup (looks cool ! and helps light up the area). You can stick the tungsten out about 3/4" if you use a piece of foil or something behind the cluster to trap the argon. Also 12-15 cpm on the argon. Most of the time I use maybe 1/2" or a little less stickout. I've also got a #12 cup that sits on a gas lens. It uses a little more argon but the stickout is ridiculous. You can use it to get down deep into nooks and crannies it need be.

The welding thing is definitely artsy. As long as I feel like I'm gaining ground I'm happy. And some days you just seem to see it better than others. And some days you wonder if you've ever picked up a torch!

I've used a Lincoln 3350 helmet that's quite good. 4 sensors, good image. The Jackson Trusight is also a 4 sensor lens pack. It has much tighter notch filters that tend to reduce the blue flare from the arc. This allows you to brighten up the whole area around the puddle and see it more clearly. This is the best that I've seen so far, although I certainly haven't seen them all !!!

[Bdflies]

Dave,
If you think TIG welding is 'artsy', then let me tell you about Oxyfuel welding! Over 40 yeas in the business and I don't think I met a dozen folks who could do it. In the aviation world, Oxyfuel welding is still seen, but TIG has replaced it to the point that we referred to it as 'the lost art'. TIG has so many advantages, it's no wonder. I used to be a fairly decent TIG weldor, but recent years found my welds looking mighty rough. After changing the outer lens, I realized I could weld better. I never used cheater lenses. Just wore readers (2.0) under the hood. After considering the improvement of the new lens, I went to the corner pharmacy and picked up the strongest readers they had. Let me tell you, with that 3.5 under the hood, I can see so well, I can weld again! Finding the 'sweet spot' for focus distance, can be a challenge and I can't use them for anything else, but man can I see that bead! Getting older seems to have some downsides.
Good for you, about the gas lens! Looking at your welds, I kinda figured such.
Question: how are you dealing with the closed tube 'pop outs'? Do you weld most of the joint, wait till it cools, then quickly close the last bit? Or drill all the junctions, so that the whole structure is a common plenum? I remember seeing an article about a guy who drilled all the intersections, then welded a couple of pipe couplers onto a longeron. He put a gauge in one and a valve in the other. Then he pressured the structure (only a few psi). Any breach of the structure would show as a pressure loss. Neat idea, I thought, but a lot of work!

Bill

[dedgemon]

I agree on the gas welding. I started with that and gas welded the tail of the Patrol. Switching to TIG was "relatively" easy after that.

I havent had any real issues with closed tubes yet. Of course it may be because I'm not good enough to get them completely sealed up. 😊

Anyone that can seal an entire fuse so that it holds pressure gets my vote for welding god.

I use the readers under the hood also. Drugstore +3's really help.

Still lots to learn about this welding thing. Fun though.