[Smoker]

Started working on my first purge box.

Looks like this, so far. Still have more to do.

 

[Smoker]

Got all my shit together and went to class... only to find a closed campus.

MF Ceasar Chavez day. Great idea for the Mexican immigrants- Close the schools for another day so people can party with alcohol and overeat.

So, got some more work done on my mini purge box.

Sliced in the vent slots with a dremel.

Used a triangle file to flare the slots. Next will be a test to check the gas flow.
I could connect gas tubes to both sides of the tube, but I would prefer to use only the right side. Will save table space, and stay out of the way of my left hand.

 

[Smoker]

Well, it wasn't a great night at Moto Welding School, but progress was made.

I got stuff ready for bubble testing the mini purge. I cut down the vent tubing, plugged one end, and smoothed out the ends with a file. The holes/slots in the tube increase in size from proximal to distal, which I thought would help even out the gas distribution. Found a water bottle large enough for the tube, and made a plan.

I know that water pressure (even the small amount in the bottle) is considerably more than ambient air pressure. So, I figured it might not work, or could take more argon flow pressure to get results. First plan is vertical bubble, second plan is horizontal bubble, third is smoke test. Whatever works.

Couldn't get a good pic, I guess because of the bottle shape. You can definitely see lots of bubbles at the top. I could see clearly in person.

In order to get bubbling out of the distal vent, I had to crank up the argon to 60cfh. So, the test worked, but the results suck.

For the horizontal bubble test, I dumped half the water and layed the bottle on its side. Was able to get bubbling from the distal vent at 20cfh.

My guess is that the vent tube will work okay in ambient air, using normal argon pressure. I'll purge the box for a minute or two over 20cfh before use. Will also figure out a removable cap for the distal end of the tube so I can remove it momentarily when purging to get argon past the distal vent.

I'll skip the smoke test. Was going to put smoke only into the bottle to evaluate the vents.

Bad news is, I forgot to bring the box home. I was going to draw the welding plate tonight and give the drawing to the instructor tomorrow. He said he might be able to get it made at his (other) job. Might be able to draw it tomorrow at class, but I hate to reduce my TIG time.

I think my project tomorrow will be a 1/8" aluminum cube. Did some aluminum welding tonight, but took forever to get the testing done.

 

[MikeGyver]

That's all Greek to me, but sounds cool!

 

[Larry02ACR]

This guy has some good videos that might help when you have some down time to watch a little YT:

 

[Smoker]

Thanks, Larry! I'll check out that video soon as I get a chance.

Here's the three inch cube, using 1/8" aluminum, from yesterday.

Will post some close-ups of the welding, and what I learned, later tonight.

 

[Mongoose]

i think youre ready for the big leagues.

 

[MikeGyver]

Dang man! That looks great!

 

[Smoker]

First problem welding the aluminum cube was, I didn't have good tools for setup. I put the aluminum against a magnet with steel bars on the outside. Didn't hold well.

My first couple of beads had a depression on each dime. Was trying different movements to fix it, but just had to slow down a little.

Some of the beads aren't on a 45 degree angle. Have to work on that next time. In the first pic I posted of the whole box, this is the reason the bottom weld isn't visible.

The fit-up wasn't ideal, so I had to use filler rod on a couple of beads. They don't look as good. Need to practice more.

 

[shinyribs]

Damn dude, you're killing it!

 

[Smoker]

After looking at the aluminum cube some more, I realized that on the beads I did with no filler- one side (yellow) is convex, and one side is concave (red). All of them have this characteristic. So, need to work on my filler rod technique, and use it.

Now that I've had a little experience with my home TIG, I can already notice a big difference between a $5,000 TIG, and a $15,000 TIG (at school). The Miller Dynasty 400 just works better.

 

[Smoker]

Wanted to try some coping welds. Got this steel tubing because it's close to the thickness of the RZ350 steel frame.

Not at all happy with the appearance, but seems like a strong weld. I think the penetration is good. No holes or gaps, so I'm okay with this first try.

Looks like a bicycle head tube & top rail.

 

[MikeGyver]

Not at all happy? You're too hard on yourself!!!!

 

[CK 187]

Wanted to try some coping welds. Got this steel tubing because it's close to the thickness of the RZ350 steel frame.

Not at all happy with the appearance, but seems like a strong weld. I think the penetration is good. No holes or gaps, so I'm okay with this first try.

Looks like a bicycle head tube & top rail.

That is a solid ass weld! 👍

 

[ToadofToadHall]

Wanted to try some coping welds. Got this steel tubing because it's close to the thickness of the RZ350 steel frame.

Not at all happy with the appearance, but seems like a strong weld. I think the penetration is good. No holes or gaps, so I'm okay with this first try.

Looks like a bicycle head tube & top rail.

Give yourself some credit! For a first coping weld thats really really good.

 

[Smoker]

More progress on the mini purge.

Added 2 aluminum cooling plates, each 3/8" thick.

I might remove the crossbars below the vent, depending on the argon flow. Will probably do a smoke test and see what it looks like.

 

[ToadofToadHall]

So it's very nicely made, but whats a purge box for exactly? (Never seen or used one) I've often seem the insides of stainless pipe being purged for hygenic welds, but a box
seems like only a small area is going to be covered by the blanket gas?

 

[Smoker]

So it's very nicely made, but whats a purge box for exactly? (Never seen or used one) I've often seem the insides of stainless pipe being purged for hygenic welds, but a box
seems like only a small area is going to be covered by the blanket gas?

This type is generally used for stainless or titanium butt welds or running practice beads. This opening is 4.25". I can make the opening larger, but I think titanium is usually welded in short runs to keep things cool. The aluminum plate sits proud of the box, so a longer coupon or part can slide across the top. Can also be set up for fillet welds, or tubing. Only the back side of the weld is purged. Well, a little more. The opening is 0.75".

Need it to keep the back side of the weld clean on stainless or titanium. Prevents "sugaring", and weakening of the weld.

I'll probably also make a purge box, just for fun. Not a sealed chamber. The box will have a lexan top, with an opening large enough to weld through.

 

[Smoker]

TIG Brazing Rod Shootout.

This is ERCuSi-A. Sizes are 1/6", 0.045", and 0.035". Steel plate is 1/16".
2% Lanthanated 1/16". #8 cup with gas lens. 50 amps. Dropped to 40 amps with 0.035 rod, 50 seemed too hot. 15cfh argon.

1/16"

0.045"

0.035"

A good welder could probably do just as well with any of the 3 rods. For a beginner like me, looks like size matters.

 

[Smoker]

Here's how the purge box is sealed.

First, I fold a piece of heavy duty aluminum foil, so it's 2 layers thick. Then, I set the welding plate on top and trace around the outside and the hole with a black marker. Then cut the hole with a scissors (a little larger than the markings).

The grate drops in the tray, with an aluminum plate on top. Then the foil, and the aluminum top plate.

I trim off the extra foil, leaving about 3/4" to wrap around the tray lip.

I sealed around the vent tube on the inside of the tray with high-temp silicone. It keeps the tube in place, and in the proper orientation. I also got a high-temp silicone plug for the end of the vent tube. I remove the plug momentarily when purging the tray to remove the last bit of air from the tube.

I leave a small gap open on the top plate to purge air and excess argon.