The V-berth head (AKA the Throne Room) is progressing, but a lot slower than I’d hoped. I still think it’ll be done before the end of April, but the honey-do list is long and there’s lots of stuff on it that has to be done to splash later this year. I’ve got a couple of welding projects that needed doing, like relocating the aluminum fuel tank fills and fabbing the stainless tube fuel fills and exhaust risers. My Millermatic 35 and Trailblazer 280NT weren’t going to do the trick. Actually, the Trailblazer could have provided the power, but I would have had to buy a TIG rig for it. The thing is, the Trailblazer’s an engine-drive welder, and the Onan gas engine in it is pretty loud. It’s fine in the boatyard, where there are no other sources of 220v power. But when I want to weld something at home on the bench, even ear muffs don’t stifle the racket.
So, with all of that rationalizing out of the way, I went and got myself an AHP AlphaTIG 200X (firstname.lastname@example.org). The results were…interesting…until I figured out the settings. There are a lot more things to adjust on this, with high frequency start and run, pulse, and even settings to keep the gas flowing after you stop welding, which I learned is critical for stainless.
AHP is an inverter TIG, which is a LOT lighter than transformer welders. For comparison’s sake, this weighs around 70lbs. My Millermatic 35 weighs 350. Granted, the Miller is a wire feed welder, but most of the weight difference is attributed to transformer vs inverter. Both machines are rated for 200A max output. The AHP has a neat feature where it’ll run off of 120 or 220, though the max amps drop to 149 with 120v input. Plus, since the input power goes through an inverter, what comes out the other end can be adjusted for amps as well as frequency; you’re not stuck with 60hz juice. After skimming through the user’s manual, I did what any right-thinking man would do: I fired that bad boy up and tried to weld…tried being the key word.
I downloaded the Miller Welding App, which gives you a ballpark idea of where the main settings should be given the type and thickness of metal you’re working with.
I can’t remember ever buying a set of gloves that were smaller than Large. Most of the time, I get XL because most manufacturers’ idea of Large can be a bit too tight. But Tillman TIG gloves are Made In USA, and they’re sized for American welders! They were actually a bit too big, but I figured I’d use them anyway. Turns out that was a bad idea. With TIG, you feed the filler rod in with one hand while the other holds the torch. Holding the torch with big gloves is no problem, but with the oversized gloves on I couldn’t manipulate and advance the filler rod well at all. I checked out Tillman’s size chart (RTFM, eh?) and ordered Medium instead…fits perfectly.
I had a couple of 1# rolls of 1/16″ 5356 aluminum alloy that were leftover from the V-strut installation, so I cut off 30 inches at a time, straightened them out, and used them for TIG filler. I suspect that as a rank beginner, it would be best for me to use 4043, but I only have that in 0.035 spoolgun wire, and that’s way too small.
My first attempt resulted in a bunch of carbon…turned out the gas was on too low. Then I kept sticking the tungsten into the plate. Keeping it 1/16″ away while holding filler rod in the other hand is a challenge. Normally, I use my left hand to steady my right when MIG welding. It gets even more complicated because the AHP comes with a foot pedal that basically works like a throttle. Mash the gas, and it puts out the max amps you set on the dial. Let off on the pedal though, and the arc cools down accordingly. It’s all super neato stuff, but this is very, very different from anything I’ve done before, and I’m no spring chicken. Old dogs, new tricks…you know the drill.
After a couple of dozen tries, though, I was able to get good penetration on 3/16″ plate (leftovers from the side decks and aft enclosure) and my beads were looking pretty close. I’ve never had a steady welding hand, so my beads tend to wander no matter what process I’m using, but it was good to finally get past the carbon fouled, stone cold mess I made with the first few attempts.
I should also note that this leftover plate has been treated poorly. It sat outside for a while, then got tossed in a box in a dusty part of my garage. All I did was hit it with a stainless brush before welding, and aluminum is very sensitive to contamination. But at this stage of the game, I was just trying to get my right hand to hold the torch steady and move in a straight line while my left hand dipped the filler and my foot worked the throttle to keep the puddle going.
I kept dipping the tungsten tip into the weld, which messes up the arc…makes it very erratic and not focused. So I repeatedly had to sharpen the tungsten. I found that a cordless drill a buddy gave me after the bastard thieves cleaned me out in 2014 worked really well to get a consistently ground point.
After several hours playing with aluminum, I switched over to stainless. I found stainless to be a lot easier to weld, so I got ambitious and started fabbing my fuel fills.
Without filler, stainless TIG is very similar to plain steel with an oxy acetylene torch. The heat just comes from electricity rather than flame. In addition to my general lack of skills, I found it very challenging to get a smooth pass working around the circumference of the tubing. Also, the necessity of post-weld argon flow for stainless was new to me. Even after you stop welding, without a constant argon shield while the metal is red-hot, critical components of the stainless alloy oxidize out, leaving not-so-stainless steel behind. The first welds were very gray because I had inadequate post-flow. For the fuel tank fills that’s not a huge issue, since the first time I fill the tanks the diesel will pickle the inside of the tube and prevent corrosion. But I eventually read the AHP manual (imagine that!) and ran the post-flow dial up to 10 seconds on the machine.
I had planned to use my ShopSmith bandsaw to make all of my cuts, since it’s miter gauge permits very accurate 90° cuts. But I wasn’t thinking about its 11″ depth limit. The Sharpie mark to the right of the bandsaw blade is where I needed to cut. Sooo…I need a metal cutting bandsaw!
I’d heard good things about Harbor Freight bandsaws for a while, as far as bang-for-the-buck goes, so that’s the one I bought. Unfortunately, the saw arrived damaged. It had been dropped motor-end down during transit, severely denting the motor end cover. The motor wouldn’t turn by hand, so I contacted HF for a return. But the box and the packing was destroyed, too, and they wouldn’t pay for a new box. So I took off the damaged motor end cap and found that the motor worked fine and the fan blades inside were undamaged. I contacted HF again and asked how much they’d refund me if I kept it as-is. The nice lady said 20% was the best she could do. So I beat the cover back into shape, painted it with some rattle can I had laying around, and reinstalled it. With the discount coupon from the initial purchase and the refund for damage, I got the saw for $160…not bad!
I was able to true up the cuts with a sander, but for the exhaust system I’m going to have to mess around with this thing and get it cutting closer to true.
Sharpie marks on the spray foam insulation tell me roughly where everything should go.
Back at the shop, I used the new HF bandsaw to cut the long, straight tube off at the proper length.
The stainless tube is lots better than the original Schedule 40 pipe. Both sides weigh as much as just one of the original, galvanized steel pipes. There’s plenty of leftover tubing, and I don’t see many more uses for that odd 2-3/8″ tubing that matched the OE Chris Craft fuel fills. So I’ll use that to practice, practice, practice before taking on the exhaust risers.