Forges 101

[CamCarpenter]

I didn't think of party stores! I will see if any of them have a helium tank they wouldn't mind getting rid of. I doubt they'll get rid of it for free, scrap metal is a lot of places lunch fund, but maybe I could buy one. Thanks, Thomas!

Cam

[ThomasPowers]

I've dug them out of their dumpsters (tips)  before. The idea is to find the last owner/user before they go to the scrap yard and talk with them.

[Frosty]

The waste transfer station I use to dump trash requires tanks NOT be tossed in the common trash bin and doesn't "notice" someone taking one or more from the pressure tank shed. There're everything from Bernzomatic butane bottles to 100lb propane tanks in it every time I visit. Tanks larger than 100lb propane cost extra to dump and get put in the scrap metal pile. The extra is to cover the employees who remove the valves and drill holes in the blow out plug. 

Un galvanized cookie/popcorn tins work just fine though you can't weld to them unless you're equipped. Pop-rivets work a treat though, better than sheet metal screws in fact. 

Frosty The Lucky.

[Mikey98118]

And let us not forget overflow cylinders on top of water headers, although they are a bit too thick walled for my preferences, and getting rid of the rubber inner cylinder adds to the work of prepping them. Also one-half of a truck muffler is an easily obtained shell source for mini oval forges.

[ArmySoldier72]

I just had a trip to the local scrap yard.  There was so much stuff, I was drooling. 

But I told him I was trying to learn smithing and asked about buying stuff, 

and of course the answer is sure I will sell anything we have at scrap price. 

There was a couple of IBeams and railroad track but for the content of this thread there was sever different styles of tanks.

So Google Metal Scrap yard and see if there is one near by. 

just a thought. 

 

ARMY

[Frosty]

You're lucky ARMY, there isn't a wrecking yard I know of in this part of Alaska that can sell to the public. They ALL operate under single buyer contracts. Everything gets crushed or shredded and gets, loaded on ships to China. Some of the older auto salvage yards will sell parts to the public but charge enough you might as well buy new. 

Frosty The Lucky.

[Mikey98118]

BXI Ceramic Fiber Thermal Insulation Board (2732F). These boards actually measure 11.81" x 7.87" x 0.39"; $20 per board through Amazon.com. This is a pretty fair deal for someone interested in lining a small box forge.

[CamCarpenter]

TL;DNR: IFI community: burner on the top or the side? (see picture)

 

I'm making a tiny shell of fire bricks and holding it together with angle iron as per Frosty's post.

My current plan is to build a little frame to keep the bricks together and support the doors on the ends. I have mine clamped horizontally, but I forgot about this one being vertical, it's simpler and will allow vent gases to escape, so I will be rotating the end bricks 90°.

I know with a venturi burner, you want it in the side so hot gas doesn't flood upward when the forge is turned off, but I'm planning on doing a blown-air system, so is the top an option again or should I still do the side?

Thanks,

Cam

[Frosty]

I prefer the burners mounted in a side near the top. Straight down directs much of the flame directly out the doorways. A good way to experiment without building lots of forges or changing things around till you find what you like is to use a garden hose and nozzle. You can arrange bricks you are (NOT going to use in your forge!) to mock up the forge's general shape and use the water stream to model the flame flow. 

Were I to make that little forge again I'd ad a split hard fire brick porch on each end. This lets you place the brick baffles where you like and it makes a fine fire proof place to rest stock.

Other than minor tweaks, which I can't seem to help but think about and make, that little forge is a well proven ad popular design.

Frosty The Lucky.

[Mikey98118]

A fan-blown burner system is quite different then a naturally aspirated burner, having a much longer pipe. People position this kind of burner wherever they find convenient; without worry over chimney effect.

[eh3]

I am trying to buy hydrophilic fumed silica but can't find any suppliers, nobody in my country sells it, tried ebay and wasted a month waiting for a package they never sent. Any Europeans know of an online store I can buy some?

[Mikey98118]

I don't know if this will help, but fumed silica is also used as a food additive; a thickener in shakes, for instance.

[Frosty]

It is also used to thicken fiberglass resins, I buy mine at a local plastics supply. Is there a shop that repairs fiberglass boats close to you, they should know of a source. 

Frosty The Lucky.

[Mikey98118]

Sealing and high-emissive coatings for ceramic fibers and other inner surfaces

Rigidized ceramic fiber products still need to be sealed for safety. Furthermore, the various coatings used for sealing tend to create a tough surface layer that holds high-emissive coatings from peeling away from the fiber’s surface; an irritating tendency that results from spreading high-emissive coatings directly on fiber products (those that aren’t rigidized first). Just as not all sealants are rated as high-emissive, not all high-emissive coatings are effective sealants, so you need to review the better-known products:

 

ITC-100 is strictly a high-emissive coating; Twenty-two years ago, I found that deliberately separating it by adding more water to a small amount in a water glass, caused the non-colloidal particles to separate out, refining the coating, and greatly increasing its emission of radiant energy. My forge went from orange to lemon-yellow incandescence, with just this change.

I’m not sure ITC is the same formula today. But. you can make a better formula, for less money than this product now costs. 100% colloidal zirconium flour can be purchased from various online sources, and mixed with phosphoric acid to make a high-emissive coating, rated above 90% “reflective” of radiant heat.

 

Zirconium silicate: Some hobbyists concoct a tough sealant coating that is also a high-emissive product; they purchase zirconium silicate flour from a pottery supplies store, and mix it down with clay powder.  Zirconium silicate, while very tough is only rated at about 70% heat reflection, but I think this figure is misleading; since the other part of its structure is clear natural crystal, which will pass light rays with very little interference, and since its operating mechanism is re-radiance, I believe its overall performance in thicker layers will prove to be considerably higher than 70%; it is also very resistant to borax, and an economical choice.

    Others use a slurry of Zircopax (a brand of zirconium silicate) mixed into to colloidal silica and a little water; the same mix is used for shell casting; mix about the consistency of latex paint,  in a clear lidded jar. The Zircopax will settle out, once you stop stirring every few minutes, and cake on the bottom of the jar, with the silica and water remaining in solution over it; until it is broken up with a butter knife, and thoroughly remixed back into solution.

Plistix 900 is rated at 70% heat reflection, and makes a tough smooth sealing coat rated for use at 3400°F.

Matrikote 90 AC Ceramic Coating (one of the product line from Allied Minerals) is a very tough hard coating containing 90.4% alumina, 1.5 silicon dioxide as a vitreous(glass-like) binder, and 2.7 % phosphorus oxide as a polymerizing binder. Matrikote is good to 3000 °F, and would prove useful as an inner layer between outer coatings of higher use temperatures and rigidized ceramic fiber products.

Satanite is probably the best-known refractory mortar for use as a hard coating/sealant over ceramic fiber board; it is use rated at 3200 F, and is easily purchased in small quantities through knife making suppliers. But, mortars are no good as flame faces, so plan on using a different finish coating over it for interior surfaces; I really like it on exterior surfaces.

BXI Ceramic Fiber Thermal Insulation Board (2732F). These boards actually measure 11.81" x 7.87" x 0.39"; $20 per board through Amazon.com

 

 

[eh3]

Thank you for the suggestions, unfortunately I can't find it as a food additive and the boat repair shops use other fillers. I found "West System 406 Colloidal Silica" in some UK shops, I read somewhere it's hydrophilic, so I'll just try to find a shop that ships to me. Again, thank you for the help.

[Frosty]

I believe that's the stuff but it's after closing here and the plastics supply I buy from is closed until Monday, so I can't call them and ask if "West System 406" is hydrophilic or hydrophobic. They'll know and can recommend a West System colloidal silica that is hydrophilic if 406 is not. 

I just wrote a sticky note to myself as a reminder but if I don't get back Monday, PM me a reminder please.

Frosty The Lucky.

[tinkertim]

Hi EH3,

If you Google for  "mbfg fumed silica" you will find a UK supplier where I ordered mine from.

Hope this helps.

Tink!

[Frosty]

Just in time Tink! The fellow I was going to ask about West System 406 won't be in the office till sometime tomorrow. 

Frosty The Lucky.

[eh3]

Thank you Tink for the suggestion I will contact this company asap. Also Frosty thank you for going the extra mile to help me.

[Frosty]

You're welcome, helping folks is why we hang here.

He won't be back in the shop till sometime today, I'll have to ask him later. It's just a local phone call, no trouble at all. Hey WAIT, that's THREE phone calls! <gasp!> Oh that's right, Steve and I like talking so it's really a good thing. 

Frosty The Lucky.

 

[CamCarpenter]

Just wanted to give you all an update:

I spoke with a local-ish blacksmith who helped me source the parts I needed and I've got the piping required for the blower design I'm going with. Fun fact, this cost me over $70CAD

 

I've welded the base of my forge (I don't have any threaded rod and I have a welder) and tacked the lid in case I need to replace bricks or use them for something else. Here's what I've got so far.

I've not had a lot of time in the shop to work on this: the boys have been sick pretty much non-stop the last two weeks. I'm just working on drilling a hole in the top (with a hole saw bit I don't care about) and that's taking a while lol. I suspect this bit will be moving from "mostly junk" to "absolutely junk" when I finish the boring process lol

I'm getting really excited for my first firing, which seems to be coming soon! Gonna keep the temps low so I don't turn my firebrick into glass lol no forge welding for me for a while.

I hope you all have been well!

Cam

[Mikey98118]

5 minutes ago, CamCarpenter said:

Fun fact, this cost me over $70CAD

Alas, the prices of pipe and tubing seem to be totally out of control here as well. Stainless steel pipe and tubing prices are even worse.

[ThomasPowers]

I've got a shelf of black pipe pieces that are threaded both ends; found them at the scrapyard for 20 USCents a pound from a remodel of a University building.  They make good rollers too.

[CamCarpenter]

Finished the forge body and cart!

Next steps: drill 3/64 hole in cap for fuel line at my Dad's drill press, get blower from my Dad and hook it up to the air/fuel line, weld the fuel cap in place and order a regulator and hose to connect the propane tank.

I can't wait to fire it!

[Mikey98118]

  It took  twenty-two years, for me to realize that pointing a burner across the floor toward its far edge, from a position on the forge shell corresponding to 3;00 PM was better, than slightly angled down toward the near edge from a 1;30 AM , because I was in love with how well that worked with a very hard flame. But what works best is what is best; not our druthers.