building a gas forge WIP (questions included)

[SHOKR]

hey all

been wanting to build a gas forge for a while, and finally started.



i bought an old freon tank, and cut front 'door' and the opening, wasnt sure how big of an opening i would need so cut the smallest to remove valve and would enlarge it if needed. i plan to use one blown burner (yet thats a whole other story for me) i plan to line it with one layer of 1' ceramic fiber, cover it with whatever equivalent of satanite i can find, then cement and lay half a brick at the bottom

today i read 4+ on how to build this and still not even close to being done!!

but baby steps

i went in the market and bought the cement, 2 bricks (will split one in two for the base, the other is just backup)


my problem is satanite, a LOT say i better use it, but its not available around here, i did find 'mortar' tho, would that replace satanite? as far as i know the satanite is mixed with water, however the seller gave me a liquid (hardner) to mix with the mortar
there was another material i dont really know the name of, but it was like very small fibers, i DOUBT that would be good for a forge!!

that is my more demanding concern, however i have few other questions

1 - the back opening, i THINK Ed Caffrey said its good for air circulation, but yet again i read so much i might be confused, does it have to be open always? and same size as the front?

2 - the burner hole in the forge, should it be at the top of the forge or bit lower? ( i know it should be tangent, but i wonder which location is best for the flame to 'hit'

3 - how big of blower (air source) would i need for that size of forge?

thanks

 

[SHOKR]

i did bit of research now and found that satanite IS mortar, so i guess i'll give it a shot, anybody would like to add info would be very glad to receive

 

[Wayne Coe]

Check out Build A Gas Forge. You should have a "back door". Make it the same size as the "front door" but you can block it down some with fire bricks. The back door allows more air to come in and reduce back pressure. Do enclose the ceramic blanket. It is friable and with the force of the burner will put fibers into the air. Now think about it, ceramic (read glass). Do you really want to be inhailing glass? You can probably use any mortor (some may just be better than others). When cured it just needs to stand up to the heat after it has cured. You might even use dirt (clay, mud). The worst that will happen is that it won't hold up to the heat and you will have to replace it with something else.

 

[SHOKR]

thanks Wayne, so apply mortar then cement? or just one of them?

 

[Wayne Coe]

Just one. Then, hopefully, you can find an Infrared Reflective product, like Plistix, Metrikote or ITC-100.

 

[SHOKR]

thanks again Wayne

actually i couldnt find any of these here locally, even called a guy who builds forges and ovens for workshops and factories and he never heard about them!

so i guess i'll just go with cement

if its not too much trouble tho, can you exlain the difference between mortar and cement? or mortar and the infrared reflective products im not sure.

thanks

 

[SHOKR]

actually never mind, i found a comparison now online.

thanks for all the help Wayne, much appreciated

 

[SHOKR]

specs of ceramic fiber



that is one giant roll!!



30cm x 80cm, bit over size but thought i can always remove excess


front cover sized, and boy is ceramic fiber bad for you!! it sticks to everything, irritates the skin and bad bad for the lungs!! looks a bit like cotton candy tho



when i did the measurements i didnt take into consideration the thickness of the fiber, so have bit extra, but again, more better than less, will cut it later





here im having trouble fitting the ceramic fiber to the end of the forge, i will have an opening but no door in the back, any suggestions on how to fit the ceramic as well and tightly as possible?

thanks

 

[C Craft]

You may have to cut too fit. However it is best to work with the inswool slightly dampened, using a spritz bottle and just give it a light spray. Dampening will help keep the fibers from going air-born while working it. Also allows you do a little shaping while it is damp. You should wear eye protection as well as a dust mask to keep from breathing the fibers. Long sleeves help to keep it off of your arms.
Dampen again before apply satanite or comparable covering. Regular cement will not work as when it gets hot is going to crack and may even pop off of the inswool! If not coated the inswool will continue to release air-born fibers with each heat!

Check out this link and you can order a number of different coatings and it will explain what each is used for!

http://www.hightemptools.com/supplies-mainpage.html

As for fitting the end for a tight fit. All you have to do is leave the inswool a little proud at the end where that will be hinged. This a pic of my forge both ends will open. This is a pic of one of the ends in the up right postion. I left 2" for the thickness of the inswool!

I left the wool almost flush to the opening where it is hinged, and I coated the ends of the inswool in the lids as well as the end of the inswool that is inside the tube. When the lid shuts against the tube the two ends push against each other (not enough to break the coating but just enough to create a seal.) The lids are locked with suitcase type latches!

The first pic is while the forge was under construction and the second is after I converted it to being PID controlled with a gas solenoid. The next pic is before I hooked up a gas solenoid to control gas flow but you can see my door has a slide that can be raised and lowered to help contain heat loss!

 

[SHOKR]

cut triangular parts to allow it to fit at the end? i will cut the excess in the roll of course, thanks for the damp tip, i did wear respirator, long sleeves and even gloves, that stuff is bad!!

i wont be applying satanite (there is non where i live, and online orders where i live would probably cost as much as ordering a ready made forge)
i will be using heat resisting cement tho, bought 25kgs that more than enough

i wont make a 'door' at the back, just and opening, and will block it with firebrick when needed.

of course my main problems will arise with the burner, still reading up on that and looking for parts

thanks C Craft

 

[Josh Dabney]

Curious what issues you've got building a blown burner for your forge ?

A blown burner is a pretty simple affair to build if you've got access to plumbing supplies. Just a bunch of pipe fittings, a couple valves, and a blower really. Far easier than building the forge itself.

http://hightemptools.com/images/forcedairburner.jpg

If you haven't already check out this thread for some good conversation on this subject-

http://knifedogs.com/showthread.php?15480-Adding-a-blower-to-a-forge

I'm sure you won't but thought I'd mention. Dont get the cart before the horse and line your forge before finishing up fabrication of feet, work rest, burner mount, front door etc. Also consider a Type K thermocouple so you know the temp your running inside the forge.

FWFW I went the PID controlled route but wouldn't bother doing that if I had to do it all again.

Keep the pics comming !

-Josh

 

[SHOKR]

my issue is i dont know where to get the burner parts, here no one uses metal pipes any more, all use pvc now. actually today i was thinking about contacting the gas company, they still use metal ones.

i discovered that the blown burner is even simpler, specially the one i saw on indian georges site. so as soon as i find a aourse im good!

LOL no worries i wasnt planning on doing that

thanks Josh

 

[SHOKR]

o yeah i saw the thread, just fprgot about it, its even simpler than indian's.

God willing i'll find the things i need soon

 

[SHOKR]

today i found someone who can cut the pipes and assemble most of the burner for me, i just need measurements, specially the blower, what size would be good for this forge?

also is it better to have the gas enter at the 90 degree coupling or before that in the main pipe? (since this sentence might not mean much) i mean like how Ed does it in this thread http://knifedogs.com/showthread.php?15480-Adding-a-blower-to-a-forge&highlight=forge or like this http://www.indiangeorgesknives.com/building_a_forge.html in Indian George's?

 

[SHOKR]

here's a little update

i didnt find any small blowers except one, it was almost double the price of the larger ones, so im since im going to use a valve anyway im thinking about getting 1/2hp blower

also the main obstacle now is the small part that injects gas into the main pipe

i kept looking for things locally, then only found the setup in the picture with aluminum, but when i went to the guy who will assemble all the pipes he said it would be really difficult to weld the aluminum, it had to be either copper or iron, so today i went for copper but after i had 2 made (one long one short) i felt its bit 'weak' so will start looking for a really narrow iron tube or pipe that would fit that small valve and one of the things in the bottom of the pic (dont know their name) problem is one is tapped the other isnt so i'll either tap it or find some kind of strong sealant/adhesive or weld it.

ideas?

btw the large square on the graph paper is 1cm, small ones are 1mm