Ribbon burner leaking?

[TadGhostal]

First post here.  I'm trying to build a ribbon burner, but my welding skills are not the greatest.  I've welded ends on steel tube, but when I stand it on end in shallow water, I see that water seeps in, meaning I'm not welding an air-tight seal on those end caps.

How important is this?  Can I seal the inside using some high temp silicon or something, or do I just need to learn to weld better (or have someone else weld it for me?)

Yes, I'm hoping someone will say either "yes, you can seal it with xxx", or "it doesn't have to be airtight", but that's probably just wishful thinking.

 

Any ideas?

 

Thanks,

Tadghostal

[Frosty]

Welcome aboard Tad, glad to have you. If you'll put your general location in the header you'll have a chance of hooking up with members living within visiting distance. At least one probably welds. 

Yeah, you can't have leaks in the plenum. Mark them, grind them to clean smooth steel and run a bead across them. Do NOT try to strike an arc on the leaks! Start the arc before it and run the bead across the leak. 

I don't think high temp silicone will survive but maybe. It would be a gamble though, you don't want to have to bust the block up to repair it if it's a problem do you? No, leaks wouldn't be the problem, the silicone coming off and plugging burner outlets would mess things up.

I don't know if it's available now but "muffler putty" would work, it's phenolic resin and will easily take 900f. If your plenum gets even close to that temp the fuel air mix will be burning IN the plenum and you'll be shutting it down to cool.

Frosty The Lucky. 

[TadGhostal]

Thanks Frosty for the info.

I didn't think about the silicon falling off and plugging the holes, and I'd forgot about the "muffler putty".  I think even if I used it and it worked it would bug me to no end - I like to fix things the right way, and anything short of a good weld just sounds hacky to me.  I guess I was just looking for validation. 

I did grind off the bad welds and re-did the beads, was about to go out and test it. 

I think the problem was that I cut end pieces to the OD, and welded them that way.  I probably would have had better results cutting them to the ID and putting them in maybe a 16th of an inch in or so, then welding them inside like that, followed by (possibly) grinding off that extra 16th of an inch - I'm just guessing here.  Anyway, thanks especially about the info on striking the bead before the leak and not at it - that will help.

[Frosty]

I find it much easier to get non leak welds if I cut it with a little extra to weld. I prefer to have the end cap overlap about the thickness of the stock all the way around. This lets me melt the extra while keeping the arc on the other side. You can over amp it slightly without the chance of burning holes.

Filling an inside corner makes intuitive sense unfortunately I find harder to get solid beads in thin stock running fillets. 1/2" steel and a stick welder? No sweat but scd. 40 pipe and a mig welder? it's a PITA with a light duty 110v 0.023 wire feed. 

That's just me though my eyes aren't as good as they used to be so I'm not much of a welder anymore. I have to cheat.

Frosty The Lucky. 

[TadGhostal]

You hit it- I’m using a flux core 110 ATM.  I have a 220 MIG/stick coming in a day or so, I might just wait-or not. Good advice on the overlap.  I should’ve asked for advice before starting.

Sun Tzu (or some other wise man) once said, “Grinder and paint make me the welder I ain’t”, which has been my motto- unfortunately neither of those help now

 

Thanks again!

 

[Frosty]

I've never thought much of flux core except for hard facing. The reason the flux on the outside of welding rod works is it burns causing a "smoke" jet that blows the air away from the gap and provides an ionized column to form a stable arc. The the mineral content in the coating forms a glassy layer to slow cooling and exclude air. 

Flux core wire on the other hand burns the flux in the center of the arc and melting wire? The shielding gas is in the center of the plasma column rather than surrounding it and keeping air off? The metal being deposited has the molten mineral content from the flux in the center of the puddle? 

I'm sure flux core works if you know how to use it but other than 400 amps constant current wire feed running hard face wire I've never had much luck with it. Believe me hard facing wire beads are NOT pretty beads, I could get them kind of smooth but they couldn't be mistaken for a weld bead.

My first welding shop teacher in jr. high told us we should learn to use a grinder and keep spray paint on hand. Another called it the welder's aerosol absolution. Many a sin under that paint. 

If you have any header paint you can hook a vacuum cleaner to the air fuel intake port and spray paint the plenum. The vacuum will draw paint into the pin holes and seal them up. If your plenum is getting hot enough to burn header paint it has problems.

Frosty The Lucky. 

[Deimos]

If you have a Mig it will be pretty easy to get something airtight. Just open up the pieces you want to weld to about 1,5 mm, then you place a block of copper/ceramic/clay on the inside with a little radius. Now if you weld the outside and burn trough the opening you get a pretty air/water tight weld. If you get better at welding you can eventually remove the piece from the inside. 

Frosty's advice is also very good, we did that with pressure tanks as well. We never stopped out longitudinal seam weld on the tank, we put a plate on each end and started and stopped on that plate, both with the Mig weld as with the Submerged Arc Welding machine. Stopping and starting is the first place where leaks or errors begin.

[JHCC]

One big advantage of FCAW is that with the flux not exposed to the air, you don't have to worry about problems with atmospheric moisture and the consequent issue of hydrogen embrittlement.

I'm no expert welder by any means, but I've managed a reasonable number of airtight and watertight welds on my ribbon burners, my water-cooled tuyere, and the bosh on my forge. If you've got the amperage, wire speed, and rate of travel dialed in -- and definitely follow Deimos's advice about not starting and stopping -- you do just fine.

6 hours ago, TadGhostal said:

Sun Tzu (or some other wise man) once said, “Grinder and paint make me the welder I ain’t”

Athanasius of Alexandria in Part 4 of Contra Gentes.

[TadGhostal]

I do have a smallish 220 50A MIG/TIG/stick welder coming on Monday.  I was able to get an airtight weld finally, but it took hours.  Not really what I’d planned for my Saturday.  
 

I also happen to have some header paint that I was planning on painting the plenum with anyway.  May as well hook up a vacuum to it- couldn’t hurt.

Thanks all for the help and advice.  

[Deimos]

Keep in mind that you need about 40A for 1mm of steel, so if you want to weld thicker steel you will need to do some more work with a grinder to make some 45° sides to everything, and preheat the metal. Also something to note about the smaller welders, keep in mind that the duty cycle is for 10 minutes, so if it says 60% duty cycle  you can weld for 6 minutes and have to let the device cool down for 4 minutes.

[TadGhostal]

I did know about the duty cycle, but the 45 degrees and preheating is great info I didn’t know.  Thanks for the heads up!

id love a better welder, but I’m not wired for it, and I really won’t be doing enough to justify the cost to the wife.

[Deimos]

Over here I am looking at a very nice 230Vac 200A stick welder, will only cost 110 euro. Maybe try to find something like that. 

[TadGhostal]

Sure I’ll look, but 110 euro?  That’s a real find if it’s in good shape.  I’ve not seen anything near that price.

also there the fact that my entire house is on a 200A service.  It’d take a LOT of flowers to convince the wifey that I need to shut off all power to the house so I can do some welding

[Frosty]

Finding used AC and AC/DC tombstone welders for very reasonable is just a matter of patience, even in Alaska I see them for under $100 frequently. I have one on my hit list as soon as I get the shop connected to the service panel. It wasn't finished when I tried catching a tree with my head. I discommend that highly.

Deimos: Thanks for the reminder about weld bead start/stop techniques. We either used a plate like you describe or more often what we called the curly cue we'd carry the weld just past the end and make a partial circle so it stopped on plain steel. 

Man it's been a long time.

Frosty The Lucky. 

[TadGhostal]

So, for instance - I see a Craftsman 230/140 DC/AC welder, $150.  BUT, it has a NEMA 6-50 plug on it.  What am I missing?  The plug is for 50 amps, so how can the welder put out that kind of amperage?

[Frosty]

The output may be rated in amps but the voltage will probably be under 12v so your wattage doesn't exceed 240v x 50 amps. 

Hopefully a sparky who knows these things will speak up and provide solid information. 

Frosty The Lucky. 

[Deimos]

The welder I was talking about has a input of 230Vac and at maximum 20A. Since a welding device is a transformer it only produces about 50VDC, this way the amp can get higher. 

Over here we have different plugs so cant tell you much about American ones. 

My very old stick welder pulls about 2,5 kW (so about 11 amps, but since it has a big start up spike I had to install a C16A breaker instead of a B16A)

The problem with starting on the piece you want to weld is that it is very cold, so you wont get a very good start, newer devices have a hot start function which will make sure you get a better start.

[TadGhostal]

Didn't know about the drop in voltage on the output - that makes sense. 

That also explains why a 50 Amp welder is so much smaller - less transforming, smaller transformer.

Once again, thanks!

[Frosty]

Might want to wait and see if I'm right or even close before you thank me. Heh, heh, heh.

Frosty The Lucky. 

[TadGhostal]

If you're wrong, you can just hang on to the thanks - you'll earn it soon enough.

BUT, The transformer thing makes sense - if you had 220V on the output, you'd not be able to have more than 50A output (on a 50 amp plug/breaker).  At half the voltage, you'd be able to put out twice the current (roughly), and so on.  So if we're putting out 230 amps AC, using a 50A plug, the voltage is definitely less (an I could even calculate it if I had the desire).  I'm just a little embarrassed that it didn't occur to me, what with my 'letronics degree and all.  Geez, I'm getting older and dumber.  Maybe the metal filings from all my bead grinding are getting through my mask?  That must be it.

 

Deimos - same thing - thanks for the info.  The NEMA plug shown is a 220V 50A max plug.  That's why I was complaining about only having a 200A home service - I was thinking 1:1, like, 200A out meant 200A in, but you (and Frosty) are obviously right.  I just hate I didn't realize/look it up.

 

[Deimos]

That is why this forum is so amazing  Don't worry about not knowing stuff, only people who wont make mistakes are dead people.

Over here we only only have 25A for the entire house. And for my shed (and the induction plate I want in the kitchen) I will get that boosted to 3x 25A

You can pretty much weld anything with a DC welder, except Aluminum. So if you just want to weld normal steel you will be good with any DC welder.  

[Deimos]

woopsie, made a big error in my explanation.

There is a difference between a welding transformer and a welding inverter. A transformer is nothing more then a box with a copper spool and a big knob, no cooling or smarty smart stuff. These have a AC input and a AC output. They have a lower output voltage and amperage then a inverter. This means that starting a weld is harder (lower voltage so less spark, meaning you will get stuck more often) Biggest downside of these is that they are heavy (mine is about 30lbs) and because of the induction over the copper coil they can trip the breaker (like mine does in my house) Plus about these is they are dirt cheap, over here you buy them 2nd hand for about 30 euro. A welding inverter uses electronics to get welding voltage, the voltage and amperage are much higher, and because they have active cooling they can also weld longer. Since they don't have big spools they also weigh a lot less (10lbs or so) They also require less power to run, so they are cheaper to use and wont trip the breaker. These will only weld DC, so you cant weld all materials and all electrodes with them. Over here the smart ones (only change the amps and the thing does the rest, also have hot start and more fancy settings) cost about 100 euro, the dumb ones go for about 80 euro. Since the voltage is much higher (about 40 to 50 volts) they also start easier and give a little wider weld.

Hope this helps.

[TadGhostal]

It does help - I think all I've dealt with was inverter.  The one coming tomorrow is a Chinese one that does MIG, FC, Lift TIG, and Stick.  It's dual voltage - will do 200A on 220V (MIG).  Should be enough.  Now, if only I could just buy additional welding skills like that.

[Deimos]

200A is about as much as you can get out of a 230Vac machine, and for any welder that is enough. It will let you weld about 5mm of steel, most angle iron or tube is about 3mm thick and you can make anything with that.

Where is the fun in buying welding skills? Learning to weld is pretty fun. Keep in mind that you need gas for MIG and TIG (Unless you work with gas filled wire for MIG) And that if you want to make very pretty TIG welds you need to protect the back of the weld with Nitrogen (else it will get black and look like cauliflower).

The easiest to learn is MIG, you can drag the nozzle over the metal if you have shaky hands. The best to learn is stick, if you can weld stick (after about 1000 sticks you will know why I say this) you can pretty much weld with anything.

Do yourself a favor and make sure you have a auto darkening welding helmet, that way you have two hands to work. 

With your MIG, make sure that when you weld your cable assembly is laying in a nice curve, that way the wire will have less resistance and wont stutter as much.

If you plan to start with TIG, you will need to learn how to sharpen the Tungsten electrodes, a belt sander is the safest option, and when you sharpen them make sure you grind them so that the grooves run across the LENGHT of the electrode, not the width (you will get a better "flame" that way, and not one that goes a mental when you weld) 

[TadGhostal]

Thanks Deimos for all the great advice! 

This all started as a step in creating a shop where I could forge blades, after I got tired of woodworking a couple of years ago.

I do have an auto-darkening helmet, and have been doing "gasless MIG" (FC), so I get what you're saying about the wire feed.  I'm getting this unit because A) the one I've been using is 110V and I'm not happy with the performance, and B)I really want to learn stick welding.

I never intended to learn welding beyond sticking some rebar on some stock to shove it into a forge, but I like making things, and welding is kinda fun.  I first made a welding table as a learning project, then I made a 2x72 belt grinder because I could, and it was way cheaper than buying one.  I've been using both for the last couple of months and they're working great so far.  Now I'm working on the forge (specifically the ribbon burner, which led to the original post) - so, I agree with you 163% (that's 100% for you metric users) - this forum is ABSOLUTELY amazing.  I'll even go as far as to say it's pretty much vital to me.  I've been lurking and reading for about two months - there's so much info here.  My head is about to explode.

Funny you mentioned the gas for MIG - I have an aluminum CO2 tank that I used for carbonation 25 years ago.  I just pulled it out last night and opened the valve (which was a little sticky).  It still had full pressure!  Still, I may be getting another tank.  I also may need to do an Argon mix - I don't know.  The gas stuff is something I have yet to learn about.