Ask your WELDING questions here.

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You got it. The tinning does the sealing, similar to soldering a hole in a radiator.

Visualize a through hole circuit board, stuffed with parts, and awaiting solder. Every through hole in that circuit board, with a part in it or no, is a fairly large pin hole. And when the solder is applied, well, those holes are gas tight.

The tinning and leveling does the sealing. You can trowel on any additional lead filler to taste. If the surface is smooth enough after floating some solder on there, well then, you're done I'd say.

I think the typical zinc-rich primer, like for weld joints, isn't a proper base for durable automotive paint. Something to consider. The tinned areas are 'galvanized', so they won't be rusting anytime soon.
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Sorry Krampus I have never used lead to fill body work.

I do know that if you do plan to tin and lead it you will not be able to weld on the steel again with out removing all the tin and lead from the surface.

Lead and zinc make welds crack and cause porosity.

It looks like you did an really good job.

I gotta say that this all this info kicks ass. Thank you KTM640Dakar for having this thread and the serving up the straight shit. Thanks to Poolside for enlightening and cautioning a noob.

Your welcome Krampus! I enjoy helping my fellow motorheads.

any word on when this welder becomes available?

Advrider's very own Loctite factory rep checking in here to offer up my very own two bits of drivel.

Years back a salty old welder discovered a wicking grade threadlocker like 290 could fill pinholes created during the welding process.

Just heat the tank up to the point you still can touch the tank without burning yourself and liberally drip and wipe the 290 all over the affected area and let cool.

You could use 290 or AA Weld Sealant (which is virtually the same thing)

Capillary action draws either product into all of the pinhole voids and the tank will be sealed.

Dirty

I read this thread a while back and decided to pick up a TIG welder. It's one of the small inverter welders that will run up to 200 amps with an air cooled Weldcraft torch. I've read everything I can get my hands on and I'm essentially teaching myself how to do it. I'm getting to the point where I can periodically lay a relatively clean bead down on mild steel but my beads are still pretty inconsistent and the bad sections still out number the good sections. I am running into a couple of things that seem to be limiting my progress though. One is that I seem to be consuming tungsten at a pretty rapid rate. I grind the 1.5 lanthanum tungsten to a point using a Sharpie hand held grinder that I picked up through Arc Zone. The point looks fine but within a couple of inches of bead, the tip seems to deteriorate. If I keep going, it eventually turns into a ball instead of a point. The gas flow looks Ok (20 CFM) even though I do get some smoke on the cup. The arc looks good until the tip starts to ball up. I think my distance is ok. The amperage I'm using appears to be within the range for the tungsten diameter I'm using. What would be your guess as to the problem?

Another question I have is concerning the technique for running the torch. Do good tig welders have the steady hands of a surgeon or are they just good a finding brace points for their hands? I mean keeping the tip an 1/8 to a 1/4 from the base metal, feeding the filler rod and operating foot switch requires a degree of skill that it appears will take a while to master. I've stuck the tip and contaminated the electrode with the filler rod a number of times when trying to free hand everything.

No Shit? Dirty...That could very well be one of the top 10 tips of all time.
Here's my question: How resistant to gas and primer/paint is the 290? If I go that route, I'd prolly have to forego any hopes of ever tinning or leading afterwards...it's a one-way road. Got any place you can point me to research this a bit more?

No Shit there Krampus!! The stuff cures to a very chemical resistant thermoset plastic and does fine with fuels of all sorts including good old petrol, primers and paints.

For another vote on this unconventional use for this product for your application call the tech. product support line at 800-LOCTITE. Make sure to tell them some wiley cat from Baton Rouge told you to call. And if a Canook answers the phone tell them to slap Sylvain on the back of the head for you.

Dirty

I called Loctite, already closed. Searched the web and Loctite's site and found this...
http://www.loctite.com/int_henkel/loctite_us/binarydata/pdf/lt1475b_DoItRight.pdf

Page 13. Looks like for my application(steel) I need to use 089 Weld Sealant/Grade AA, but I'm having a difficult time getting product info on the site...it doesn't show up when I do a search. But I'm on the right track.

OK
First, what polarity is the welder set at? AC? DC+ or DC- ?

The positive half of an AC cycle contains the major amount of heat in an arc. In other words when you set a TIG welder to DC+ the electrode will melt down. Never run DC+ when you TIG weld because your Tungsten will melt before your work. Also when running AC on your TIG welder the Tungsten electrode will see DC+ half the time and DC- half the time. This will also cause the tungsten electrode to melt on the DC+ half of the cycle.

So when using AC to TIG weld you can expect your tungsten to melt to a round end eventualy. Weld aluminum with AC only, not steel or stainless.

Use DC- for stainless and steel. Using DC- will focus most of the heat into the metal and not on your tungsten electrode. Your electrode will stay sharp longer using DC- but will also eventualy round over in time.

To help make a Tungsten last longer use as large of a diameter electrode as is practical. A 1/8 inch diameter Tungsten electrode will handle heat input better and last longer than a smaller one. Also the flow rate of sheilding gas is inportant. With an aircooled TIG torch the shielding gas is your only source of torch cooling so always run a post flow of 10 to 15 seconds to let the torch flow gas through the torch so the electrode is not glowing red before the gas stops running. 25 CFH is a good flow rate for most small aircooled torches.

And finally, practice, practice, practice. It is my opinion that TIG welding requires the most skill of all the welding processes. Use what ever you can to brace your hands or parts to make your welding as easy as possible. It is easier to make a good weld when you are sitting on a comfortable stool and have something to rest your hands on.

Don't get discouraged.

That is a very cool trick!!!!!!!

Sorry, I was going to add that. It's set to DCEN which should be correct. It behaves as if it is set to DCEP or AC however. I don't have any refference points to tell what the difference is though. The tungsten does get hot. Hotter than red hot. More like white hot. Perhaps my gas flow is still to low?

I discovered something else. I was using an .040 tungsten to weld thin wall (.0035) 5/8 4130 tubing. I was running 40 amps, pulsing at 100 cps with 80 %spent at peak amperage. I decided to try the next size tungsten, a 1/16 (.060). Using that size, my tip sure does last a lot longer. The trouble is that the charts I have say that the .040 should be good for 15-80 amps when running DCEN and the .060 range is 70-150 amps when running DCEN. Are these charts wrong? I have the tip extending about the diameter of the cap so it shouldn't be a problem with cooling. If it is, would a gas lens help?

The other thing I'm noticing is that when welding this tubing, which I've notched to fit, I have a very hard time seeing the edges of the tubing. I more often than not end up welding just one edge rather than both pieces together. Is there a trade secret associated with how to actually see the edges you're welding when doing this stuff?

You may already know more than this, but... The only trick I've picked up regarding this problem (and I learned it about MIG, but it may apply to your problem) is to train your eyes to never look at the arc, but only watch the puddle - both the hot side and the side that's solidifying. I found that watching the puddle gave me much better vision to watch the joint I'm following. And watching the "freeze zone" helps regulate your speed to just stay ahead. Watching the puddle also made me see better the amount of penetration without looking at the arc itself which just destroys your vision of the joint. You may already be focusing on the puddle as you dab the filler rod.

Yeah, that makes sense. I'll try that. The other thing I was wondering is that perhaps when welding at this low of amperage I need to drop the darkness of my shade a couple of notches. Don't want to blind myself trying it though. I need to get someone who knows what they are doing to watch and tell me what I'm doing wrong. I think I found someone to do that. The guy teaches welding certification classes at one of the local suppliers and has experience welding aircraft tubing.

Looks like this thread isn't being monitored at this point in time so I thought I'd update it with my findings.

I did get the guy to come over and give me some pointers. There were a couple of issues I had. One of them was identified by Mark in the previous post. Keep your eye on the puddle. This is harder to do with TIG than it is with Oxy-Acetylene in that the arc is much brighter and is easy to get distracted and watch the arc instead of the puddle. He also got me to change over from a regular collate to a gas lens. The gas flow is much smoother with the lens and the arc seems to be more stable. Another area is the angle of the grind on the tungsten. He was grinding his tungsten to much more of an angle than I was. Changing to the angle he was using seemed to narrow the arc and permit better control over the puddle. I did also reduce the shade level of my visor to 10 and that does allow me to see what I'm doing better than I was before. Yet another thing he pointed out was that with the thin rod I was using (also .0035) the feed rate of the filler rod needed to be much higher and that required more coordination than I had given my experience level. A little thicker rod (which he brought with him) permitted me to add to the puddle at a much more comfortable rate given the amperage and the material I was welding on (4130 tubing).

The result of these changes is that I can now lay down a reasonable bead in a straight line. Not everyone is perfect but they are beads and the correct amount of penetration is present in the bead. The next task is to learn to weld joints that intersect at different angles. I'm still having problems in that area in that I'll get penetration on one side of the joint but not the other. More later.

one trick i've picked up for grinding tungstens is to taper them so that the taper starts at least 3x the diameter back from the tip. i try to put some curve on it like the nosecone shape below. then i grind a very small 90 degree cone to get rid of the sharp tip, which would erode quickly if i left it there. this shape stays hot so you get a stable arc, but lasts better than straight cones in my experience. you can also fudge using a bigger tungsten on lower current, saving you from switching (or buying) a bunch of different collet assemblies for the torch.



if you use an automatic mask, you may want to give a standard 4x5 lense mask a try. i use a gold colored lense which somehow helps reduce the eyestrain (turns out to also help my eyes focus and adjust to the light), and i think the one i have is a 9. i pretty much only use auto lenses for tacking and out of position stuff.

i'm not sure if it's been mentioned, but it helps to hold the filler metal nearly perpendicular to the tungsten. both the tungsten and the filler then should be in the same plane. i usually tilt the tungsten to push the arc by about 10 or 15 degrees, then the filler is 10-15 degress above the path i'm on.

that's pretty great you know someone who's so qualified to help you. luckily for my learning curve, i had an angry (but fun) machinist watching over my shoulder and threatening to use the .45 he just made from scratch.

good luck

Mike

Thanks I will try grinding my tungsten in the manor you descibe. I didn't actually know this guy. I tracked him down through a local supplier. He teaches TIG welding and has expirience with welding aircraft tubing. The guy knew what he was doing. He can lay down a beautiful weld on this thin wall tubing (using my equipment) along a section that is notched to mate into another piece of tubing. It's difficult for me because of the constantly changing angles in addition to the problem I'm having with getting a pool formed on both of the adjacent parts. The guy turned out to be a nice guy as well and offered to help as much as I needed. I paid in cash of course for his time and everybody loves cash:)

you really should isolate the things you're trying to learn. depending on where you are skill wise, here's a list of steps i've used to learn and to show other people to weld. hop in on the list where ever your skills currently are

run a bead with no filler along some .080" or so thick sheet steel. get the width down, puddle control, welding speed. you can look at the heat affected zone to see how consistant you are. it's a good tell tale since it shows heat input, which can be all over the place even if your weld looks right. strive for a very even band, and do welds at least 6 inches long so you learn to move the torch with your hand and not just your fingertips. the medium thickness plate will be forgiving, but still show a good heat affected zone. practice starts and stops.

do the above adding filler metal. again, look at the heat affected zone. practice starts and stops. stops will be more critical now, you need to add an extra dab of filler and slowly ramp down the current to prevent craters.

practice some butt joints to get control of your puddle, and fusing it across the joint without filler at first, then work with filler. you should break the joints and look for full penetration. you want to be right on the edge of burning though in order to get full penentration. again, look at heat affected zone and do at least 6" sections.

next move on to straight T joints on the same ~.080". break them and make sure you burned into the corner of the joint.

you can work your way to thinner material on each of these as you progress. make sure to move the torch through the path you want to weld each time, so make sure you have clearance and are able to maniulate it to the correct orientation. i prop my hand off of my pinky or some other finger to stabilize it. i'm not one of those gifted people who can tig or stick weld with their arms fully extended, and not shake at all. most people aren't, but you can still learn to make nice welds.

once you get this down, tube joints will be a more reasonable challenge. i usually do a tube joint by tacking symmetrically, then welding in 4 sections. it makes your starts and stops more critical, but 1/4 of the perimeter is much easier to manipulate the torch around. starts and stops are a tedious task, not a highly skilled task. you trade tedious for skill based on your own level of skill. also, get a stainless toothbrush and clean the area you will weld right before you weld it. and get in the habit of sanding off the black scale/oxide on the tube ends. you want raw clean steel. tig filler has some de-oxidizers, but nothing like stick flux.

good luck,
Mike