Mini Gasser ?

[LastRonin]

I was given this little tank and am interested in possibly trying to use it to make a small propane forge. It is about 11.5" long and 7.5" diameter. There's already a port about 2" from one end that a burner could probably be easily inserted into. I want to try to use it mainly to make small pw billets for jewelry/decorational pieces... and if I get the nerves, maybe even a small knife in the not-too-far future. And maybe even other non pw small projects. 

 

Now the questions...lol:

 

1. Would 1" of kaowool be sufficient? that would leave me about a 5" diameter space... the 2" I see recommended most places would only leave about 3" diameter opening... which would you guys recommend? (I already have the kaowool in both thicknesses, given to me by some fellows who insulate boilers and gas turbines)

 

2. I'm leaning toward a Frosty T-burner. Would a 3/4" be too much? If so, what size/type would ya'll recommend?

 

3. If I make the end that has the port (It's where that black block is attached) the back, would that be an ok place to insert the burner, or should I cut a new hole more centered?

 

 

 

Any other thoughts, suggestions or ideas will be welcomed.

[Frosty]

A 3/4" would be a bit much but you can turn it down. I'm a firm believer in the "it's better to have it and not need it than need it and not have it" school of thought. A 1/2" T burner is good for about 150-175 cu/in volume so you'd need two of them.

 

I'm a fan of a stainless shell, it reflects IR better than steel so you keep more heat in the forge where I paid it to be.

 

A 5" dia. ID is a perfectly workable forge, a 9.5"-11.5" length is going to make for less than even heat though putting the burner at the back and positioning it to make a strong vortex might be a different story. A 3/4" T burner is in the 50% more gun than the numbers say it needs too.

 

I'm thinking this is going to be one H-O-T forge with one little drawback, the forge exhaust is going to be coming pretty straight out of the opening, even if it's spinning in a strong vortex. It might drive heat right up any long stock or at the smith.

 

I'm really looking forward to how this works. Don't be afraid to experiment you don't need to worry about washing the interior for short test firings and you can pull the Kaowool and rearrange it frequently. If I had a few sq/ft I think I'd be playing with that size cylinder to see how it fires. I can get ss stove pipe really close to that size 2 miles from here. The Kaowool is about 57 miles though. ABOUT 57 miles. <wink> That'd be the Anchorage office of EJ Bartells, my go to guys for refractories.

 

This project will be on my to watch list for sure.

 

Frosty The Lucky.

[ThomasPowers]

Since you are designing this as a welding forge how do you plan to keep the flux from damaging the kaowool?

Since you are designing this as a welding forge 2" of insulation would help---but that narrows the usable space way down---1" will work but you will be using more gas over it's lifetime.

[LastRonin]

A 3/4" would be a bit much but you can turn it down. I'm a firm believer in the "it's better to have it and not need it than need it and not have it" school of thought. A 1/2" T burner is good for about 150-175 cu/in volume so you'd need two of them.
 
I'm a fan of a stainless shell, it reflects IR better than steel so you keep more heat in the forge where I paid it to be.
 
A 5" dia. ID is a perfectly workable forge, a 9.5"-11.5" length is going to make for less than even heat though putting the burner at the back and positioning it to make a strong vortex might be a different story. A 3/4" T burner is in the 50% more gun than the numbers say it needs too.
 
I'm thinking this is going to be one H-O-T forge with one little drawback, the forge exhaust is going to be coming pretty straight out of the opening, even if it's spinning in a strong vortex. It might drive heat right up any long stock or at the smith.
 
I'm really looking forward to how this works. Don't be afraid to experiment you don't need to worry about washing the interior for short test firings and you can pull the Kaowool and rearrange it frequently. If I had a few sq/ft I think I'd be playing with that size cylinder to see how it fires. I can get ss stove pipe really close to that size 2 miles from here. The Kaowool is about 57 miles though. ABOUT 57 miles. <wink> That'd be the Anchorage office of EJ Bartells, my go to guys for refractories.
 
This project will be on my to watch list for sure.
 
Frosty The Lucky.

 

Thanks Frosty. I have a garden trash bag full of kaowool. Maybe a pair of 90º tongs...

 

Since you are designing this as a welding forge how do you plan to keep the flux from damaging the kaowool?
Since you are designing this as a welding forge 2" of insulation would help---but that narrows the usable space way down---1" will work but you will be using more gas over it's lifetime.

Thomas, I was thinking of using either small pieces of kiln shelf, or pouring my own using the idea I read on here somewhere about using porcelain slip with sawdust to make floor plates.

[LastRonin]

I got the little tank stripped down today, all the extra little connections that were on it ground loose. Three of them had tubes that went almost all the way across the tank. The big receiver port for what I thought at first was a pressure switch (but believe now to have been a magnetic triggered microswitch due to the float with a magnet in it that was around the dip tube when I pulled it out) cleared out easily. The hole left there looks almost perfect for a 3/4" pipe fitting to slip through with a little room to spare, so I shouldn't have a problem fitting the burner in there. And there are three 8/32 threaded bolt holes I can use to mount a guide for aligning the burner. I cut a rectangle approximately 3 1/2"h x 4"w out of the 'front' for a work window/dragon mouth :D (it IS called dragon's breath). I used two old pieces of 316 ss pipe strap to make the support legs. The strap is about 2" wide and 1/8" thick and was for hanging 8" fire sprinkler pipe. I shaped it to fit the curve of the tank. The tank has two threaded (10/32) lugs already welded to the bottom that used to mount it to the frame it started on. I think I might re-use it as a base for the forge, but mount the tank to it with the brackets I made instead of just the two lugs through the ss sheetmetal. I need to drill the holes in the middle of the straps to pass the lugs through and cut the excess length off the one foot on each strap, then drill the mounting bolt hole in that foot on each of the straps. The straps should hold the bottom of the tank about an inch to an inch and a half up off the surface beneath it. 

 

I still need to finish scrounging/purchasing the components for the burner, a regulator and kiln shelf (or kaolin). I'm going to see if I can get the kaowool in it without having to cut the entire end out. The batteries in my camera are dead so I'll have to get pics either tomorrow or next weekend when I am back home from working out of town. So far everything is ss, so I'm going to try to scavenge ss pipe and fittings for my burner too.

 

I'm going to try to get some kaowool in it tomorrow after church to see how the space looks inside and can decide how thick I want it to be.

 

Question: When I ground out the welds that held all the little hose attachments and stuff and knocked them out, there are several (5 I believe) holes about 3/8" diameter along the top where the pieces were. Should I worry about filling them in with something or just let the kaowool, stiffener and reflective coating do that task?

[jcornell]

 

In keeping with the dragon theme, you could take a bolt with two washers and have the threaded end sticking out, using the washers to close off the hole.

 

Personally, I'd just leave them there - the kaowool, once you've used rigidizer, will suffice to block these holes.

[LastRonin]

It's coming together. I did a test run without the rigidizer so I can see how a couple different burner ideas work. This was a compressed air blown slotted pipe burner running at 2-3 psi at the regulator with a needle-valve for fine-tuning. The air was fed from a compressor with regulator pressure at 35 psi and a needle-valve for finetuning. It works pretty well. Going to try a couple more burner configurations before I finalize the build. Coolest thing about this build is that I have been lucky/diligent enough with my scrounging and such that the only purchased things for the forge as pictured are the propane regulator (0-60 psi , gotten for US 2$ at scrap yard) and the propane tank refill.

[LastRonin]

 I finally got the parts together to put together a 3/4" Frosty T-burner... HOLY COW!!! that will be my burner. I don't know if I can tweak the tip depth any to get a better result as far as lower psi needed on my propane, but at 6 psi it is more than plenty forging hot.  I'm talking mid-high yellow... move up to 9 psi and I'm getting white hot. This is without rigidizer, refractory coating or ITC(or equivalent) coating yet. So the original picture I was going to post is meaningless. Hopefully I can get my rigidizer and a layer of refractory in it by next weekend.

[LastRonin]

PICTURES!

[LastRonin]

[LastRonin]

And finally the video!

[Frosty]

 That's screaming hot, is that a 1" burner? You can turn that puppy WAY down.

 

Frosty The Lucky.

[LastRonin]

Frosty: First off, thank you for your time you have spent sharing your knowledge and experience on here.
Secondly, to answer your question, it's a 3/4". I agreed with your statement from post 2 on this thread, "it's better to have it and not need it than need it and not have it".

I am building this forge to do pattern welding, so I wanted it to be able to scream. (I like to think of it as more of a roar... of the wee dragon.) :)

[LastRonin]

I CAN WELD!

 

Lol... I managed a forge-weld last weekend. Started what I hope to be a PW billet worth making a blade from. Welded half a broken Nicholson file to a piece of A36. The weld seems solid. the piece so far is about 1 1/8" wide by 5/16" thick and about 6" long. I ran out of propane while flattening and prepping for the first cut and restack. I'm currently working out of state, due to head back home late Saturday the 13th... maybe I'll refill my tank and try to pick up where I left off.

[Frosty]

You bet that baby can weld. Congrats. That's one of the down sides of a propane burner, they're loud, gun or N A, they roar. Folk driving in our driveway can hear the forge before they get to the house. Nobody coming over to play in the shop needs to knock at the house door but they DO have to shout to get my attention when they come in the shop. Unless I happen to be looking that is.

 

I'm happy as a clam in sand to pass on what I've picked up, I've been shown most everything I know so what the hey. <grin>

 

Frosty The Lucky.

[LastRonin]

Picked up half a box of Blue Ram HS refractory, it was given to me (hhappy dance). Going to try ffrosty's tube in a tube idea to redo my little minigasser.

[LastRonin]

Latest.

I relined it using BlueRam HS. Did it the way I understood Frosty to have done... two cardboard tubes with a 1/2" gap between them mounted on end on a board. Then used a stick and mallet to ram the refractory in, packing it until the mallet bounced off without noticeable further packing. Added a little at a time this way until the space was filled.

I then unfastened the tubes from the board and inserted them into the forge body to mark the burner hole location. A quick two minutes with the right size hole saw while the refractory was still fresh and voila... a nice clean hole.

Let it set for two days then removed the inside tube and stuck a 100W bulb in it for four days.

Took the outer cardboard off and wrapped two layers of 1" thick Inswool around it...  and dropped it.

After a few choice words, I wet the broken edges, used some fresh refractory to pack between them and coated the outside with about a 1/4" coating (after packing by hand) all around . Carefully re wrapped the Inswool.. Wrapped that with the Sunday funnies and taped with paper tape. Barely managed to slide that into the body. 

Too frustrated to wait longer, I reinstalled the 3/4" Frosty T-burner, set my pressure to 4# and lit it off for about five minutes. 

After letting it cool for thirty minutes I lit it for ten. Let it cool an hour and turned up the pressure to 10# and ran it for ten minutes. 

By this time, the refractory was no longer blue. It had turned a light grey and when I tapped it with a piece of steel, it went "rink" instead of "think" and didn't leave a mark. 

Thrilled, I lit it off and made a hand sickle for clearing the weeds along my ditch. Used a piece of spring about 3/8" diameter to make it from.  I'll have to get pics of the sickle later. I used a claw hammer handle I picked up that someone had snapped right at the head and threw away.

[LastRonin]

 

A shot of the flame shape.

Edited May 6, 2015 by LastRonin

[LastRonin]

[LastRonin]

I'm attaching daytime photos of the lined forge. Any comments will be appreciated. I do plan to make a flat insert from the BlueRam HS to bring the floor up level with the bottom opening of the pass-through in the back. 

[LastRonin]

Here are a couple pics showing the propane feed into my Frosty T-burner and the minor mod to his plans. I'd love it if Frosty would give me his opinion on it.

 

ok, my phone is giving me trouble uploading them. I'll try again in a moment.

[LastRonin]

Ok, got them loaded.

[Frosty]

The flame shape looked good in the pic. You mounted the jet differently than I did on the last few I made but it works. I'd say the fitting threaded into the T allows you to adjust the jet depth without having to remove, cut and clean it up like I do. I think it's a better set up than my last incarnation set up.

I'm changing the way I mount the mig tip in mine next time. I used the brass fittings because I couldn't find 1/4" scd. 80 pipe without ordering it. I understand one of the suppliers caries it in stock now so I'll be calling around. That will simplify mounting the jet and making it adjustable a LOT easier.

Oh yeah, my opinion . . . The burner looks good, will it weld? 

Frosty The Lucky.

[LastRonin]

The flame shape looked good in the pic. You mounted the jet differently than I did on the last few I made but it works. I'd say the fitting threaded into the T allows you to adjust the jet depth without having to remove, cut and clean it up like I do. I think it's a better set up than my last incarnation set up.

I'm changing the way I mount the mig tip in mine next time. I used the brass fittings because I couldn't find 1/4" scd. 80 pipe without ordering it. I understand one of the suppliers caries it in stock now so I'll be calling around. That will simplify mounting the jet and making it adjustable a LOT easier.

Oh yeah, my opinion . . . The burner looks good, will it weld? 

Frosty The Lucky.

Thanks for replying. I'm glad you approve.

Yessir, it will weld. I want to try a bit of mokume sometime, I'm hoping I can turn it down far enough. Lol, just kidding. It seems pretty stable as low as 4 psi. Highest I've turned it is about 17 psi. It was screaming at that high. I ran it at about 12-13.