Forges 101

[Michael jude]

Gentleman thank you all for putting this thread together.

Having read through its entirety a sticking point remains for me. I realize there are many suitable solutions and therefor asking for the right way is naive. However in your opinions what is the hierarchy of forge liners from the ceramic fiber blanket inward? For the sake of argument money and availability are no constraints. 

The players I can come up with off the top my head are Kastolite 30, Satanite, itc-100, Zirconium silicate, bentonite, glass micro spheres, high alumina kiln shelving, Veegum\Zirconium silicate

Understanding that many of these are used in concert including successful thicknesses of application and percentages added of lets say micro spheres to Kastolite or Zirconium silicate in kitty litter derived bentonite etc. would be very helpful. 

it may seem that i’m looking for create the “perfect forge”, in truth I just want don't to waste my money putting expensive materials like itc-100 on a liner that is quick to crumble. or adding a potentially unnecessary layer of Satanite between kastolite and a bentonite kiln wash. I do understand that with enough use just about everything is consumable, just prefer building for efficiency and longevity. 

Thank you 

 

[Mikey98118]

Those are pretty broad questions. Let's try things another way; why don't you tell us something about what you are looking to do with the forge, so we can pick and choose among those materials, to see what is best for you.

[Michael jude]

Sure thing, 

The next forge I build, my first propane, will be a tool for tool construction. The tools I will be producing immediately are a froe, draw knifes, adze, carving knives and various chisels. Its use will inevitably include welding.

I am not wedded to a design yet, but likely, a single burner tube or D with pass through. A minimum chamber floor of 5” wide 9” deep. over the past few months I have been collecting various materials, presently I have enough ceramic fiber to build a crematorium, (unfortunately rated 2300), ridgedizer, and a little tub of itc-100. I have been looking to source a local castable but the best I can find is this stuff but the silica/alumina ratio looks backwards?

http://alsey.com/assets/pdf/msds/SDS_HI-CAST_45_R20151215.pdf

a vertical casting furnace is also right down the road. 

I was thinking about Kastolite30, with glass balloons, constructed at a half inch thickness, (ideal ratio welcome) then a layer of satanite,  itc-100 with a finish of the itc-100 wash.  dried slow and fired between layers. though that is a total guess

having used neither satanite  or itc-100 and the proprietary formula of the latter being a secret I can't tell if it is redundant on the really quite high alumina satanite. I could be wrong but I think I read here that itc-100 is a flux shield as well as the IR benefit.

As for doors is there any benefit to refractory hard brick over brick shaped castable?

finally wondering if people have had trouble with the drying and first fire of kastolite? if so has anyone tried adding paper pulp?

thanks again

 

[Mikey98118]

I recommend a two-gallon forge using a non-refillable freon or helium cylinder from a party store or HVAC contractor for its shell. If you just cannot

resist the temptation to overbuild your first forge, go for a five-gallon propane cylinder from U-haul.

Use one 1/2" burner for a two-gallon forge, or one 3,4" burner for a five-gallon forge. What design? A "T" burner or a Reil burner with the full MIG tip modification described.

There is nothing wrong with the 2300 F ceramic fiber, so long as you use colloidal silica rigidizer with it, a 1/2" hot face layer of Kast-O-lite 30  from Wayne (use fording in some silica bubbles are still a good idea).

No (TC; use Zircopax with 5 % bentonite; DO NOT USE KITTY LITTER FOR THIS. As clay powder it is nearly colloidal; litter ain't.

These paths will both give you a very satisfactory tool forge with minimum fuss.

You ver' lucky; miserable Mikey no like talk of easy path...only do this for tool forge 

[Mikey98118]

Michael J.

A tube forge is usually placed horizontally; if you arrange for it to also be placed vertically it can be used as a casting furnace. The biggest of various minor changes needed for this is a change in your planning. A casting furnace has its sizes based on the largest crucible you intend to fit in it, plus some additional diameter for the burner flame to curl around.

You also must place a single burner within a couple of inches of the bottom end of the "furnace," rather than the middle of the "forge."  So, to get the based performance out of it, as a forge, you should place a second smaller burner farther toward the exhaust opening, and leave it off when casting.

[Retiry]

On 7/30/2016 at 4:31 PM, Frosty said:

 

I can't find your article about the how to for the Truck burner.

[Binesman]

I believe you are referring to the T burner not truck.  Its pinned under the gas forges section.  I do not remember the exact title but it says frosty T burner in the title.

[Buzzkill]

8 hours ago, Retiry said:

I can't find your article about the how to for the Truck burner.

T Burner Directions finished.pdf

[Retiry]

12 hours ago, Binesman said:

I believe you are referring to the T burner not truck.  Its pinned under the gas forges section.  I do not remember the exact title but it says frosty T burner in the title.

The truck was my phone's contribution.

I like the Ron Riel design so I'm going to switch to a brass plug and drill it to .030. I'm going to use stainless for the nozzle end. 3/4" pipe. I chose this design because I have seen the build start to finish.  The design has less machining involved, not that I'm afraid of it , I just want to get hammering.  Christmas is coming quick.

[Mikey98118]

Enough with the refractory cement already

Different efractory cement brands are as unlike as castable refractory brands are. One thing they all have in common is a  complete absence of grog. Grog is needed to provide dimensional stability, to keep a thick layer of refractory, like a forge hot-face from cracking apart under repeated thermal cycling. Refractory types of cement are made to glue refractory bricks together, with thin layers.

[Mikey98118]

On 11/15/2017 at 10:57 AM, Retiry said:

esign so I'm going to switch to a brass plug and drill it to .030. I'm going to use stainless for the nozzle end. 3/4" pipe. I chose this design because I have seen the build start to finish.  The design has less machining involved, not that I'm afraid of it , I just want to get hammering.  Christmas is coming quick.

.030" is the smallest hole size available in a MIG contact tip; it is usually installed on a 1/2"  size burner. If that is what you plan to build, and plan to drill your own gas orifice .028 would be a better size for your drill bit.

That would take a #70 bit.

[Charles R. Stevens]

.023 is the smallest nominal size. I don't know what the actual OD is Mike. 

[Jasent]

On 11/21/2017 at 12:48 AM, Charles R. Stevens said:

 

It's very close to .030. Some are .027-.029

[Charles R. Stevens]

So just about the .028 Mike is looking for. 

 

 

[Mikey98118]

That depends on the manufacturing source; those smaller orifice sizes are from foreign sources, and you will be tossing dice about actual orifice sizes.  Older tips, including foreign, were designed to work on American made welding wire, and will run between 030" and .031" inside diameter. Newer foreign tips are made to work on foreign welding wire.
 

So, to stand a chance of getting the smaller diameters, you have to choose millimeter threaded tips, and it is still a game of chance; been there done that.

[Mikey98118]

So, if we want the smaller orifice sizes, drilling your own hole in half-hard brass is the surest way, followed by needle tubing as the next best method. MIG tips are a long way third for coming up with orifices under .030" consistently.

[Retiry]

Well I have actually bought the parts and have changed to a final design.  Since I have found and downloaded the plans for Frostys T burner.  I like the simplistic design. As for the forge, I'm using 8x8 tubing with 3/16 walls and 14" long. 11/2 pipe to mount burner. Refractory, 2 layers of 1 in 8#  ends will be covered except the opening being even with the brick on the bottom and in the back the top of the inside opening will be covered. The back will be attached, the front will have offset hinges. I'm using rigidizer coated with Plistex. The brick will have one layer under it..  Last week I bought an anvil for 275.00 100 pounder. Turns out it weighs 160 and it's the first run of the Fisher Eagle 1843. The mounts gave it away when I looked it up in Anvils in American. The patent was awarded in 1844. Mine has no number. I was surprised there's no ring, just a thud but a great rebound. 2/3 and about 6 bounces.

The top half in the back will be covered.

[Mikey98118]

8" is about the right diameter for a #10 tin can, as for instance a coffee-can forge or casting furnace.

[Mikey98118]

You can turn down the gas pressure on a 1/2 " T burner to serve, but stuffing a half brick in there is going to make it pretty hard to contain the flame in the forge.

[Retiry]

On 11/24/2017 at 8:50 PM, Mikey98118 said:

 

That is why I'm going to use an adjustable regulator 0 to 30 and a needle valve. So the flow and pressure can be varied. Because the brick insulates. Under the brick will only be one layer.

Man, finding schedule 80 in an 1/8 inch nipple is a chore. I'm going to pack each wall after I soak with the rigidizer about a half inch. It's 6# so it will be as dense as 8#  so it will be more of 1 1/2 ".  Then coat with Plistex. The next one will be 10 inch SQ. Tube I like the length being 14".

I got another question; I'm thinking about going to 10 " dia. Schedule 40 pipe. There is a coating on it, does that have to be removed? I believe it to be ziebart.

[bluesman7]

10" schedule 40 pipe is 40 lbs per foot. An old propane tank is much more appropriate. 

[Retiry]

On 11/25/2017 at 10:45 AM, bluesman7 said:

 

That 40 lbs. Is for a completely different use. I'm just going to use it for a frame to hold refractory in place. It's under no stress and it doesn't get all that hot. I've seen portable air tanks used and they are thinner. They actually use coffee cans. I worked with sch40 and for this use it's plenty thick. Thanks for you input.

[Jasent]

30 minutes ago, Retiry said:

 

I believe he is saying it's too heavy and something lighter would be easier to work with

[Retiry]

I have a piece laying around,  it's free. Yes its heavy but I go by use what you have first. Anyone know if I should remove the black coating?

[timgunn1962]

It depends a lot on what the black coating is, and where. That may depend on where it came from.

If it's just an enamel-type paint on the outside, it'll be fine. If it's an epoxy-tar internal (or internal/external) coating, and you have the means to remove it, I'd be inclined to do so.

With 2 layers of 1",  8 lb/cu ft blanket inside and a homebrewed porcelain clay/Zircopax coating, I've not had a problem with leaving the original paint on compressor tanks, though the stick-on logos tend to get smelly and shrivel up. Compressor tanks are not treated inside, so I reasoned that I could just hit the outside with a flapdisk if the paint caused a problem down the line.

Getting rid of an internal coating after the forge is built is a whole different ballgame.