Printable View
Try this; tape a piece of aluminum foil over both open pipe ends. Next, put a small hole in both. Put your tig torch against one hole and inject your inert gas until you feel it has filled the cavity. More is better. Next, tape the two small holes shut & begin welding. It has worked well for me. Sometimes I prefer this method because it allows repositioning the workpiece without having a purge hose connected.
Here are some more pics of the headers. I zoomed in on the passenger side only so you can see greater detail. The headers are symmetrical left to right.
One of my design goals was to simplify the number of different angle cuts I needed to make. These headers only require 90 degree and 45 degree bends. I made a simple cutting jig to allow me to make fast, easy, and accurate cuts out of the 180 degree mandrel bends I bought.
https://thefactoryfiveforum.com/atta...5&d=1549372018
Attachment 101777 Attachment 101778 Attachment 101779 Attachment 101780
I may try that in conjunction with the solar flux. That way as the gas leaks out the unwelded joints I will still be protected. Your right in that having a purge tube in one end is awkward as you are constantly having to twist / reposition the part.Quote:
Originally Posted by lance corsi
Imo, the Solar flux is unnecessary and if you plan on tig welding, any sort of foreign substance that may be drawn into the weld is a bad idea. I use pure argon. Clean the parts well with acetone. Fit the parts as close as is practically possible. Argon is heavier than air, so if you're worried about it escaping, tape the bottom 2/3 of the pipe joint. Use at least 3 tacks. Use stitch welds until you're sure it will not warp beyond use. Use same or higher grade filler rod as your base metal. Practice on a scrap piece first. When welding tubing, I like to use 1/16 tungsten and a .04 dia filler rod.
The easy way to get good at welding is to weld a lot.
The hard way to get good at welding is to weld a lot.
You pick!
Looks great Hobby, I use the same method that lance is suggesting to purge the tubes and it works great with the freedom to roll the piece as needed while welding. As Lance has said clean both the inside and outside of the tube with acetone. Looking forward to seeing the finished product.
Are you going to have room for mufflers? I know you don't need them at the Glen but believe you will at Lime Rock, Palmer and Club Motorsport. If space is tight we sell inserts that can be installed in the tailpipe's that will knock the noise down 4-6 DB and they are easy to remove when not needed.
Love it!!!! All good advise, thanks for tips.Quote:
Originally Posted by lance corsi
I'm thinking of putting in a removable straight section out the back that is sized for a Magna Flow inline muffler. That way I can run straight pipes or the muffler sections if needed.Quote:
Originally Posted by Mitch Wright
Lance, I can only find 0.035 and 0.045 308L rod. Which would you go with, or am I just splitting hairs here?Quote:
Originally Posted by lance corsi
Either diameter would suffice. I avoid the L designated rod, as it contains trace elements of lead, which is not easy to weld with. You could jump up to 316 ss if it comes in the small diameters. Plain 308 would work also. Use 15-18 cfph of gas, DC straight polarity. I use the 2% thoriated tungsten.
Trace amounts...sorry!Quote:
Originally Posted by lance corsi
I don't know how I forgot this, but one of the most important things to get right when trying to lay down that perfect bead- get comfortable, or as comfortable as possible. Half the time you will be welding in awkward positions, so if at all possible, do yourself a favor and get comfy!
Pretty sure the "L" designation means low carbon.Quote:
Originally Posted by lance corsi
308L: Low carbon would be 0.04% and lower.
308H: between 0.04 - 0.08%
308: maximum of 0.08%
I use 2% lanthanated electrodes in my inverter type TIG welder, works well with mild steel, stainless, aluminum so I do not have to have multiple tungsten types, plus its what is recommended by the manufacturer :)
Early on in my TIG efforts for my 818 (was my first TIG and so far only)... Arts818 you can see I've done a fair amount of it, and a lot I didn't describe...
I rigged up a T in the Argon and ran it to a medical pinch hose line, letting a bit of gas go to the back-purge needs. Stuffed a balloon on one end of whatever, taped the other end. As long as the balloon was just puffed up I knew there was some flow, turn if off the balloon "dies" = yes it works.
Then I bought the Solarflux. Ouch at 38$ a can. It does work but you need to have access to the inside of the joint to paste it in. And a little bit of learning curve on mixing and applying, it's not like icing a cake. Some joints you can't reach when assembled, and pasting in halves then butting the pipes doesn't let it work very well and if you don't really paste it up very nicely, it does not protect. It turns to glass like material and that doesn't bother me if it is in exhaust path. IF you can still reach the joint you can kind-of chip it out with a sharp tool, tapping, but necessary? You MUST use the right alcohol, I tried whatever I had around and it was not good. So get a bottle of Heet for that, every gas station has it. It is great for things like the flange to pipe, since that is rather hard to setup a purge (can be done but this is easier).
So if you want Solarflux and didn't buy it, pm me and you'll get plenty of mine. No point in blowing a wad on the tiny bit you need. One can is a lifetime supply for non commercial work like us guys.
Finally though I did buy a dual gas flow setup off ebay. This one was the cheapest, and while not exotic nor perfect (touchy to adjust until I modified the valves using my mini-lathe). It does work just fine. Costs $109. Now you have nice control. But again are you going to keep using this or one shot deal? If you bought a TIG machine I'd say you justified getting this already.
Ebay look for:
DUAL HTP Argon CO2 Mig Tig Flow meter Regulator Welding Weld Double Backpurge
One more thing - not only comfy but excellent view, close up. I bought the highest magnification drug-store reading glasses I could find. I use them when welding and another pair on my electronics workbench. I had a prescription pair made years ago, for 5" from my nose. Perfect they were but over time got scratched and dinged. The drug store variety have proved just as good and are next to nothing to buy. Close up vision doing TIG is wonderful IMHO.Quote:
Originally Posted by lance corsi
Here are my thoughts on mock up and final assembly. Tack each tube together with only 2 small fusion tacks at each joint and do a test fit. Then break each pipe down and final weld each joint one at a time using the paste and a lot of tack welds to keep each new piece in place. Building each pipe up one joint at a time.Quote:
Originally Posted by aquillen
On the exterior of the flange to pipe I was thinking about using silicon bronze filler rod and TIG brazing them. I have seen that recommended by a few header fabrication shops.
Attachment 101797
Man, wish I knew that before I bought my 1lb lifetime supply. :pQuote:
Originally Posted by aquillen
Out of curiousity, what did you have to fix to get the regulators working well?Quote:
Originally Posted by aquillen
As I recall, the adjuster thumbscrews are just needle valves, and they are sloppy. Turn them and they move back a bit, and even change with vibration. So getting exact flow was hard to do. I (may - don't recall now) have cut a groove on the adjuster shafts with my lathe so o-rings from my assortment boxes would fit in. Anyway I'm sure I fitted little o-rings and silicone grease on them so the adjuster screws would be more firm but also slide on the rings and not change settings on their own. The dual flow control turned out to be "cat's meow" for me.
Ok I just learned this from another forum where some car guys are using Onshape CAD. Onshape has this thing called link sharing where I can post a link to my cad file and anyone can load it up and play with it in their browser window.
You have to try this!
Link to my 3D solid model header file
Use the toolbar at the bottom of the page for pan / zoom / rotate / etc
Slick!
I added the collectors to the shared CAD model.
Click the picture to interact with the 3D model.
https://thefactoryfiveforum.com/atta...9&d=1549555064
Nice!
It looks like you're using the collector "kits". I started with those, but it seemed too challenging to assemble them in place and layout the system. Went with slip-fit inlet types and it helped greatly. However, I was building the headers in place after giving up on modeling them. Chop saw, belt sander, masking tape, and band-aid for dents in my head from falling parts... I work with Solidworks daily, and this method was less frustrating!
Regarding assy & distortion;
First thing I did was fix the muffler positions and mounting, including the v-band flanges at the mufflers. For the header fab, I cut/fit parts in place and masking taped them together. Then I tacked each joint making sure it was solid and stable. Then I took it to a professional sheetmetal/welder supplier I use, because I can't weld for sh!t. He welded the whole thing in 1 one shot while I held it. Then 2 weeks later his son welded the other bank. In the end, they came out identical in fit- way out at the end of the mufflers both were "up" 1/4" from their saddle, that's it! I was pleasantly surprised and happy that only a mount adjustment was required, as I honestly though it would be a mess.
* I have 2ea 3-to-1 collector kits available at a steep discount for anyone building...
Funny, I moved to modeling in CAD because I got frustrated trying to tape and hold the pieces up under the car by myself! I only ordered just enough tubing to make it work so I did not want to do a bunch of trial and error cuts. It was tricky at first, modeling the pipes, but once I got the hang of it I worked through a few configurations and settled on the one that had only 1 or 2 welds per pipe. I figure the less I need to cut / weld the more accurate the outcome will be.Quote:
Originally Posted by DSR-3
I've had similar thoughts about just tacking everything up and taking it to a professional welder, but I really want to learn how to do this so I'm jumping in with both feet. I've gotten a lot of great advice and encouragement from Lance, Mitch, Zach and others, so I'm going to give it my best shot.Quote:
Originally Posted by DSR-3
Oh and I can't forget to thank you for sharing your pics, they helped a lot.
John, as Lance pointed out the more you weld the better you get. When TIG welding I always weld some practice pieces to get some muscle memory and to get comfortable and figure out what I will use to rest my right arm on. When building headers you have plenty of scrap so we will have a lot to practice with, go for it.
I've never used that solar flux. I'm very curious to hear what you think about it and hopefully see some pictures of the results.
When I did my sidepipes, I bought a Smith dual regulator and it worked great for back-purging. Stainless bracketry presents a problem, though, as there may not be an enclosed space on the backside of the weld. For those situations I have usually figured out some kind of copper backing plate, which works well, but the solar flux might be even better. I wonder if it cleans easily from parts exposed to view.
I was in the same situation as you when I did my sidepipes for the Cobra. I cut my TIG welding teeth on that project. The biggest thing that helped me was just buying a 2-foot length of straight stainless pipe, cutting about a 1/2-inch off of it, and welding it back on. I repeated that about 15 times until I was making beads that looked decent. It was 16-gauge material and I tried both 1/16 and 0.045" filler rod. On these thin-metal, low-amp welds, adding rod is like throwing ice on the puddle and sucks the heat right out of the base metal - causing the puddle to immediately move around. Managing that is what's tricky. My tendency was to go too slow, making the heat-affected zone too big and resulting in a gray weld (I was also using a normal #7 size cup. Larger may be better.). The 0.045 rod doesn't chill the puddle as fast as 1/16 does, but I think anything smaller might melt before you get it into the puddle.
When I make the exhaust for this car I'm going to do another round of practice. I will be using a very large pyrex cup and I will play around more with the pulser to see if I can manage the heat input a little better. I probably wouldn't care so much if not for these Instagram welders making feel incompetent, ha!
I think your right in that the Solar Flux would be great for exposed brackets and such (I have not tried it yet). I ended up buying a dual regulator like others have suggested and will back purge the pipes the traditional way. Hey, I'm already in this far, what's another hundred bucks right ;)Quote:
Originally Posted by Zach34
I'm doing the same thing you did, I bought a 2 ft. section of straight tube to practice on. I am cutting it up into 1 in slices and trying to weld them back together again. Emphasis on trying!
What I'm finding hard with my practice pieces is rolling my wrist around at the same arc radius as the tubing and keeping my arc length short and the torch angle reasonable. With such small diameter tubing, something gets out of wack after only about one inch of weld travel. I either get to much arc length or my torch angle gets too far from perpendicular.
I am noticing that the torch is fighting me when trying to roll it in my fingers. Having to put a lot of effort into fighting the resistance makes me shake and I get terrible torch control. I'm not sure if the hose is not flexible enough even though it is a "Super Flex" hose on a WP17F torch.
I use a log like toy that belongs to my dog or a piece of 2-2.5 tubing to rest my wrist on to allow some freedom of movement. I have the same problem I will tense up and my hand starts shaking. I will say the more I weld the more relaxed I get on a project.
SOLAR FLUX -
It is great for open work like the flanges to pipes. About the only removal is chip it or grind it. If reachable then belt or disc sanding or even sandblasting works pretty good but of course you have to avoid cutting into the metal.
You can get creative, for example shape aluminum foil over an area and feed purge "inside" it, instead of the SF...
I have benign tremors which is pretty strong shaking, usually when trying to do fine work. I find ways to support my wrists and arms, get the rest of my body relaxed, and get really close to the work visually as I mentioned above. This lets me get it done. Once every so often though, I have to just go do something else and come back in an hour or so. Frustrating but I won't let it end my projects. Attitude is almost everything.
I agree - it quickly becomes apparent that torch angle is critical. Leaning it over just a little results in having to pump more heat in to maintain the puddle, and that throws everything out of whack.
I've never made a good TIG weld with my wrist completely unsupported. My best welds always involved resting my hand on a guide that followed the line I needed to make. It's just tough to figure out a solution for round tube.
This is one of the issues that I'm trying to figure out. I'm thinking of making a guide that attaches to my welding cup that I can drag along the circumference to maintain arc length so I can focus on torch angle more. Basically trying to remove as many of the working variables as I can. Maybe if I make the guide a bit wider and give it a concave radius the same as the tube it can help me maintain torch angle and arc length!Quote:
Originally Posted by Zach34
Equally as important as torch angle is arc length. On rounded surfaces, this is more pronounced. Starts and stops are inevitable. Practice making restarts so that the look is as if you hadn't stopped. That is the trick, because rarely will you be able to complete the entire length of your weld without repositioning yourself or stopping to get more filler rod.
I am finding that it takes 5 or 6 restarts to get around the 1.5" tube circumference. I get maybe 3/4" of weld before I'm out of position and can no longer see the puddle clearly. On your restarts, do you start one or two dabs back over the previous end point or do you start right at the end and maybe back up just a bit to ensure a solid connection to the previous weld?Quote:
Originally Posted by lance corsi
I've had good results both of these ways - go back just a little bit and warm up the puddle, or jump ahead to new area and then quickly go back to the existing puddle. Either way you do want the earlier puddle to melt in with the new start.Quote:
Originally Posted by Hobby Racer
I built a rotating table to try doing a complete rotation pass when making my rod end joints for the rear suspension. Couldn't get used to working with forced speed of rotation (I could adjust the speed but my technique just wasn't good enough). Funny thing, just a few weeks later my friends at my local metal fab business called me over to repair their rotation machine which was big enough to do whatever comes in. Replaced the motor controller which had fried. If I'd known they had it I'd have bummed time on it earlier but by then I already had my joints made with stop/start passes.
Hobby, I usually just return to where I last stopped, but I try not to overlap my previous bead because it will leave a large bead where the overlap is. Sometimes at the restart, I dwell a split second to remelt the previous, then as I move forward, I judiciously add filler so as not to mound up the bead at the start. It takes a bit of practice, but everybody finally has to come to terms with it. You will develop your own technique for what works best for you. I used to get the shakes too, but I'm used to it now.Quote:
Originally Posted by Hobby Racer
Tig welding is a constant balancing act between amperage, arc length, torch angle, amount of filler added, and hand-eye coordination. Try laying on your back welding overhead with the foot pedal between your knees!! It's a challenge! That's probably what I like most about it. A good welder can find employment wherever he chooses to land. Welding is one of the handiest skills I've ever learned.
This is the first joint that I'm not embarrassed to show :rolleyes: Learning to TIG weld on thin wall stainless tubing is probably not the best idea. But the project requires it so like I said before, jump-in with both feet.
Using the dual regulator to back purge really helps, the back side is actually nicer looking than the top side! I just ran out of gas so its off to the welding supply store Monday morning for a refill.
Attachment 102257 Attachment 102258
On the contrary, I think your decision to learn on the thin wall stuff is the best decision. Looking pretty good so far. Those look like solid welds. No reason to think they would fail from what I can see. Now it's just a matter of how good you want to get at the aestherics.
Thanks for the encouragement! My main goal is to achieve solid / sound weld joints, I don't want to have to go back and fix these later. Aesthetics are nice, and will probably come with practice, but are a secondary consideration. In between practice welding I am starting to tack up the primary tubes. I build these make shift jigs on my fab table to hold the tubes in place and tack them together with tiny fusion welds.Quote:
Originally Posted by Zach34
Attachment 102410 Attachment 102411
I finished welding each of the primary tubes for both sides. Now I'm getting ready to TIG braze the tubes to the flange and then the weld on the collectors.
https://thefactoryfiveforum.com/atta...3&d=1550684807
Attachment 102484 Attachment 102485
I've got to say that the welding table I bought has been money well spent. It is great for laying out jobs like this. With all the holes in the top, it makes it super easy to lock things in place.
Nice work John.
Always an inspiration John. I'm planning on doing somthing similar. I got a pair of raptor headers included with the purchase of my car from the previous owner and we'll see if we can cut them and add tubing to make them work or start from scratch.
Looking like you know what your'e doing! Tip - if you haven't already, jig up some 90 degree scraps and practice that style joint. Technique of course is different than rounding outside tubing. The difference in thicknesses and the angle makes for popping a hole through the pipe pretty easy.
That is exactly what I'm doing today. I bought a 1 1/2" hole saw to cut holes in a 3/8" flat plate to simulate the header flange and I will practice welding in scrap tubes. The silicon bronze filler melts at a lower temperature than the base metal so I hope to be able to braze the thick flange to the thin tube without blowing holes in the tubing.Quote:
Originally Posted by aquillen
Since I'm very new to TIG welding I mock up and practice each joint configuration until I feel confident enough to light up on the real pieces.
I also took on tig. Made turbo headers and working on exhaust for my 33. Very tight with no room so a lot of pie parts. Not to fancy, just old farmer learning new trick.
https://thefactoryfiveforum.com/atta...8&d=1551132975
I got some time to work on the headers again today. They are now together enough to test fit on the car. I welded the tubes together in preparation for welding on the collectors. That involves building up weld material between the tubes and then grinding back just enough so the collector slips on. That way you don't have a large gap to fill when finish welding the collectors on later. The Solar Flux really came in handy here as there was no easy way to back purge these pipes when welding them together.
Attachment 102785 Attachment 102784 Attachment 102783
I have only tack welded the tubes to the flanges for now. Figured I'd wait and do the final perimeter welds on both sides last just in case anything needs to come apart and get redone! I will use the Solar Flux again when welding the outside of the tubes to the flange as it will fully penetrate to the inside of the tubes where it would be difficult to back purge.
Attachment 102788 Attachment 102789