Author Topic: Pin2Hot's 73 CB750 (Read 56611 times)

Pin2Hot · « **Reply #75 on:** January 18, 2017, 12:50:52 PM »

Cal, excellent advice. I've been trying to think of every option possible to avoid TIGing this thing but it looks like I'm gonna have to face reality. TIG it is. I have the exact set up you mentioned and I started practicing last night with some thin plate. It went . . . OK. Definitely learned a lot but I think I can handle this job. I'll post pics when I'm done.

calj737 · « **Reply #76 on:** January 18, 2017, 01:27:47 PM »

I'l tell you a few more tricks I use when doing a tank/thin sheet. I use a 75/25 mix of Ar/He. The He mixture allows you to run far lower amps (like 25-30) to get the proper fusion without the heat. He ionizes far more efficiently than Ar and thus your arc is hotter, and your heat shield is cooler, so the HAZ is much smaller. If your welder is Inverter-based, use a 2% Lanthated tungsten, ground to a decent point.

Even if you can only get a 90/10 mix, its worth the effort to swap your tank (or rent one from your LWS for the duration). I keep a big bottle of 100%, a large bottle of 75/25 and another large 75/25 CO2 for MIG. Got it all covered. I use the He mix for all aluminum welding due to far better penetration without the amps. In fact, I was welding 1.50 blocks to a .625 rods earlier with a 17 air-cooled and a #5 using 160 amps. Try that with 100% Argon!

Pin2Hot · « **Reply #77 on:** January 23, 2017, 07:34:34 AM »

I spent some of the weekend practicing my fillet welds with a bit of success. I also called my welding supplier and got some numbers on He/Ar mix and it's pretty much out of my price range. The cheapest route I found would be to get an 80 cf bottle of helium and use a Y connector to mix the argon but even then, it's an additional $160 bucks after bottle rental and gas cost.

Test set up:

Weld example:

Speaking with a co-worker of mine, he suggests that my fillets are too large. I was having trouble getting the weld pool to be mobile enough unless I put more rod into the pool, thus, adding heat and spending too much time in one spot. I'm using a 1/8" electrode with 0.045 ER70S-2 filler rod. I was using a gas lens with a #6 cup (all I have until my new gas lens kit shows up today). I have a bunch of other test strips ready to go so I'll spend some more time this week nailing down my technique and shrinking down the weld size. I was deforming the crap out of my test pieces so I can only imagine what it'd do to my tank. Slowly but surly....

calj737 · « **Reply #78 on:** January 23, 2017, 07:40:38 AM »

Reduce the filler rod diameter! The larger the rod, the faster/more you cool the puddle. Try using a #6 with a 1/16" wire. I think you'll find it much easier to control the total heat. You can also notice the Heat Affected Zone (the discolored area above/below your weld) is very large. That's an indication you're loitering with the pool and traveling too slow. This is caused in part by too large a wire, and adding too much wire.

Go small! Add just a little. In fact, use 1/16" wire and "lay wire" it in front of the puddle and just travel. Move slowly/fast enough that the puddle burns in on the toes, and bump along. With a smaller wire, you can also increase your tungsten stick out. The tighter the arc, the better it burns in and reduces the HAZ.

Pin2Hot · « **Reply #79 on:** January 23, 2017, 08:02:32 AM »

I misspoke. I'm using a 1/16" electrode....

Maybe I'm a bit cornfused, is 0.045 filler rod still too large? I'll give the lay-wire technique a try as well.

calj737 · « **Reply #80 on:** January 23, 2017, 08:38:08 AM »

Sorry, I mis-read your fill wire as 1/8". If the tungsten is 1/16" and the wire is 0.045, simply lay it and travel. Don't weave. You're not trying to create structural weld, only a welded seam.

You could even drop to a #5 cup to help isolate the arc even more if you have one.

Pin2Hot · « **Reply #81 on:** February 06, 2017, 07:57:05 PM »

I just thought of something. Am I just asking for trouble with my paint on the tank if there's hot oil just on the other side? Can it get hot enough to mess up the paint? I probably should have thought about this before I got to this point.

So I found my solution to my welding woes: silicon bronze. It flows easily and I don't have to put in nearly as much heat. I've got some cratering / pitting due to my bad tie-ins but I plan to go back and grind them out and reflow it all to make it nice and smooth. I'd say it's going pretty well which is a huge relief.

All tacked.

Jumping around to minimize heat input.

I have most of it welded up by now but a few tricky spots remain. Once I'm totally done, I'll pressure test the tank to check for leaks using soapy water and pressurizing the main gas tank a bit. Once I'm satisfied it's leak free, I get to do it all over again to add a second "wall" which will prevent hot oil from contacting a surface that has gas. Basically creating a tiny air gap between the walls. I'll again check for leaks then seal it up.

palepainter · « **Reply #82 on:** February 06, 2017, 08:16:54 PM »

I did this to a Harley years ago. I added a spacer wall between the two containment areas as well. I drilled a small hole in the half inch space between the two cells and filled it with expanding foam to help prevent some of the heat transfer to the gas. The tanks were seal coated in the oil portion as well as the gas after all the welding. Regarding the heat affecting the paint, you should be fine if you use an epoxy primer. Your bigger concern will be no air bubbles in your bondo mix if it is needed.

The welds are looking great!!

Pin2Hot · « **Reply #83 on:** February 27, 2017, 06:45:52 AM »

It's kind of amazing how quickly things go when you've done them before...

After 3 weeks of getting the first set of walls welded in and pressure tested, it took me just under two days to get the final set put in place. I spent considerable time leak/pressure testing the first set to make 100% certain no fuel would leach into the oil portion of the tank. Turns out, the trickiest part was at the bottom folded edge of the stock tank. When it's stamped from the factory, a tiny tiny channel is created that runs the perimeter of the tank completely preventing you from sealing it off unless you cut it and weld it from the edge.

Ignoring my wonderful weld blowout, I had to cut through the entire edge of the tank to seal it off from the larger section.

I made a little seal that fits into the filler neck where I pressurized the tank to 2-3 psi and sprayed soapy water all over the tank to look for bubbles, found quite a few:

Once all the leaks were stopped up, I started on the second set of walls so that no hot oil surface is ever in direct contact with a surface that holds gas. This should help reduce the amount of heat transfer between hot oil and gas but it's not going to be perfect. I've been using a contour gauge to help me match the surfaces, creating a cardboard pattern then slowly building it up piece by piece. The process worked out much better the second time around as I had the first wall to guide me.

So a day after starting, I finished the welds (brazes, whatever) and pressure tested again. I drilled a small hole between the first and second sets of walls so that I could pressurize the tiny area between the two walls to ensure the 2nd set was leak proof.

Now the actual fun part begins, welding in parts from the stock tank I chopped up literally 6 years ago. Drain plug, send and return. Not shown is the air/oil separator but that'll go in as well. The trick will be getting the tank to vent properly but I think it's possible.

calj737 · « **Reply #84 on:** February 27, 2017, 07:34:46 AM »

Braze vs Weld depends upon what filler you use. Welding fuses two surface by joining them with a filler rod. Brazing filler rod melts much lower temp than the parent metal, so you are "soldering" the joint closed in essence. You can use Silicon Bronze filler with a TIG rod and it will work very well to put the tank shell back together. Less heat, less distortion and you can water quench the shell to eliminate the "oil canning" from heat.

Your work looks pretty darn good under there

Personally, I think I might have lined both volumes independently with Caswell and not worried about pin holes or leaks or heat transfer. the oil should never get hot enough to effect the fuel, especially if you're running an oil-cooler.

Pin2Hot · « **Reply #85 on:** February 27, 2017, 07:53:55 AM »

Thanks, Cal! I do plan to line both sides of the tank with Caswell so there's some extra extra protection there. I hadn't planned on running an oil cooler but there's still time if it's the right thing to do.

Pin2Hot · « **Reply #86 on:** March 02, 2017, 06:06:13 PM »

I'm running into an interesting issue finding a bung for the supply and return from my oil "tank". I've decided to weld in some new female bungs to the bottom of the tank but can't seem to find a good supply of -8AN female steel bungs. Seems as though NPT is a lot more common. I want to use a female bung to minimize the distance coming out of the tank as I may run into clearance issues with the valve cover. I'm going to 90 directly out of the tank and head back towards the rear then route down to the engine.

I think my best option is to use a 1/2" NPT female bung, then use a 1/2 NPT to -8AN 90 adapter to accomplish this. Sound right? Having a helluva time finding the right weld bung.

calj737 · « **Reply #87 on:** March 02, 2017, 06:48:44 PM »

http://www.verociousmotorsports.com/Shop-by-Category/AN-Weld-Bungs/Vibrant-AN-Female-Weld-Bung

Pin2Hot · « **Reply #88 on:** March 02, 2017, 06:57:12 PM »

Way to make me look like a jerk, CAL!

Man I thought I'd scouuuuured the internet. Thanks a ton!

Pin2Hot · « **Reply #89 on:** March 05, 2017, 06:17:26 PM »

After close to 8 years out of the frame, the engine returns. Albeit temporarily.

Jnel · « **Reply #90 on:** March 05, 2017, 08:33:52 PM »

This is a great thread. I can't tell you how much I've learned. Like a good book, i couldn't stop reading and when i got to the end, i wanted more. Its amazing the length of time that the process has taken, but yet the focus and vision remain strong. Great job.

Cal... you have a plethora of knowledge!

SOHC4 Cafe Racer Fan · « **Reply #91 on:** March 05, 2017, 08:55:04 PM »

Quote from: Jnel on March 05, 2017, 08:33:52 PM

Cal... you have a plethora of knowledge!

Bootsey · « **Reply #92 on:** March 06, 2017, 01:13:11 AM »

Quote

Cal... you have a plethora of knowledge!

The suppository of all wisdom, as the oh so wise ex Prime Minister of Australia so eloquently put it.

Jnel · « **Reply #93 on:** March 06, 2017, 03:58:56 AM »

Very true. What would we do without YouTube

Sent from my SAMSUNG-SM-G935A using Tapatalk

Pin2Hot · « **Reply #94 on:** March 06, 2017, 06:17:48 AM »

Quote from: Bootsey on March 06, 2017, 01:13:11 AM

Quote

Cal... you have a plethora of knowledge!

The suppository of all wisdom, as the oh so wise ex Prime Minister of Australia so eloquently put it.

I can't tell you how well this sums up this project, great video. I stand on the shoulders of giants (Cal), all thanks to the internet. It's responses like this and the people of this forum that have helped me maintain the focus for so long and I'm so glad it's able to help others along the way. I've leeched from the internet and this is my small way of giving back.

Another internet based project that has inspired me is SV Seeker. If you haven't seen Doug's project, I highly recommend stocking up on food and shutting yourself in to watch his YouTube channel, it's simply amazing.
https://www.youtube.com/user/submarineboat/videos

I'm fortunate enough to go work on this project in June with the hopes of having this bike done by then to ride it to Tulsa.

Jnel, thanks for the kind words. I'll keep posting until this bike is done.

calj737 · « **Reply #95 on:** March 06, 2017, 06:57:36 AM »

There's more truth in the maxim; "If you believe you have all the answers, then you're asking the wrong questions" than most people consider. I know some about a lot, a lot about a little, and less about more than I wish.

Jnel · « **Reply #96 on:** March 06, 2017, 07:27:24 AM »

Godffery · « **Reply #97 on:** March 08, 2017, 07:22:34 PM »

Interesting tank work your doing there.

Pin2Hot · « **Reply #98 on:** March 09, 2017, 02:27:52 PM »

Thanks, all of the oil line fittings came in this week with the exception of the female bungs which show up tomorrow.

After getting the supply, return and vent lines sorted, I'll button up the tank and start on the other million things that need to be finished.

Pin2Hot · « **Reply #99 on:** March 27, 2017, 06:37:26 AM »

I haven't had a whole lot of time in the garage the past few weeks but I was able to weld in the supply and return oil line bungs as well as the oil drain plug. A LOT of time was spend making sure the bungs were in the right orientation so the fittings would be in the right place when tightened. I'm pretty sure these bungs are being welded in upside down but it was the best orientation for this purpose and I don't think it'll cause any problems.

Here's a question, should I use some kind of dope or tape on the 90 fittings when tightening them into the bungs? I can see that tape could protrude into the tank and eventually end up in the engine so I'm wary of using it.

Cutting holes, re-using the same oil drain plug from the stock tank:

Getting bung orientation down before welding them in:

Brazing them in:

Still to do, weld in the oil-air separator and tank vent:

Just for fun, here's the inside of the oil-air separator in case anyone hasn't ever seen it. I'm cutting mine in half due to the set up of my oil tank, essentially splitting the main vent from the oil-air separator. I'll weld in the main vent separately:

These last bits should go pretty quickly so I'm hoping to have this tank finally finished so I can move on to the rear hoop and monoshock mounts. My deadline is June 2, gotta keep moving.

News:

Author Topic: Pin2Hot's 73 CB750 (Read 56611 times)