kraythe

The Brick Pile Forge (A Guide for those new to Gas Forges)

Recommended Posts

Over the time I have been visiting this forge I have seen a lot of people come through and ask about all sorts of designs of forges. Most of the people posting such threads are actually new to using a gas forge and often new to smithing. I have advised many of these newer smiths to first build a brick pile forge, use that a while and then go to something more serious once you figure out how big you will need. So now I wanted to make a definitive post as a guide for these people.

The forge will have an internal size of 9" x 4.5" x 6.5", or 263 cubic inches. It is, however, easily reconfigured to be smaller, shorter, wider or whatever you need for your particular tasks in the shop. That is the beauty of a brick pile forge, it can be reconfigured at will and allows the smith to see what size they need in the end. This forge is not the end all-be-all of smithing forges. It is a starter forge and as you work with it, you will learn a ton about how forges work and will grow into more efficient systems. The brick pile forge is so versatile that occasionally I will toss one together just to do some specific task that doesn't work well in my main forge.

Forge Materials:

  • About 10 to 15 Soft insulating bricks, rated 2300 degrees farenheit.
  • 3 Hard firebricks.
  • Metal Table

Burner Materials:
  • 1" to ¾" Black Iron T fitting (1" across the top and 3/4" on the leg of the T)
  • ¾" to to 1" Black Iron reducer
  • ¾" x 6" Black Iron Pipe Nipple
  • High Pressure Propane Regulator
  • Propane Pressure Gage
  • ¼" Propane Rated hose with Fuel Threaded ends (available at welding supply stores)
  • ¼" Propane Rated Flashback Supressor (available at welding supply stores)
  • ¼" Fuel to normal pipe thread converter (available at welding supply stores)
  • ¼" Ball Valve
  • ¼" Brass Pipe Nipple (4")
  • ¼" Brass pipe Nippel (smallest)
  • ¼" Brass Pipe Straight Connector
  • ¼" Brass Pipe to 1/8" Copper Compression Fitting
  • (2) ⅛" Brass Pipe Compression nuts
  • 24" flexible copper pipe
  • ⅛" Compression to normal pipe Nipple
  • .025 MIG Tip
  • Propane rated thread sealant.

Tools (Basic):
  • Copper Compression Hose Flare Fitting
  • Tap for your MIG tip thread (varies by the tip brand)
  • Tap for ⅛" pipe thread
  • Couple of Crescent Wrenches
  • Drill
  • 2" Hole Saw
  • Hacksaw
  • Reducer for ¾" to drill bit size for the tap.
  • Plumber's torch with click starter

Tools (Best):
  • Drill Press rather than drill
  • Dremmel with Cut-off wheel

Propane Supply Assembly
post-15449-0-53257100-1325552339_thumb.j post-15449-0-49959300-1325552341_thumb.j post-15449-0-37726000-1325552343_thumb.jpost-15449-0-24598300-1325552345_thumb.j post-15449-0-06312100-1325552347_thumb.j

First tap the 1/8" compression to normal pipe nipple with the tap for your MIG tip. The right tap to use depends on the tip brand that you are using. If you ask a welding supply store they can supply you (or at lest tell you) the right size. Then cut about ⅛" off of your MIG tip and put propane sealant on the threads and screw it into the tapped fitting securely. Next attach the copper flexible hose to the compression fitting by putting on the compression nut and then flaring the tubing and finally screwing the compression nut on the fitting you tapped. The goal of the flexible copper tip is to get a good nice gas tight seal without constraining yourself with rigid pipe. Next put the compression nut on the other side of the tubing and flare that. Take the ¼" pipe to compression fitting and attach the other end of the flexible copper tubing to this fitting. Then attach the converter fitting to a small pipe nipple then to the straight connector and then to the longer pipe nipple. The extra parts make this assembly easy to use on other burners and other projects in the future. Finally attach the 4" brass pipe nipple to the ball valve, then attach the ball valve to the fuel to pipe thread converter. use propane sealant on all threaded connections.

Fuel hoses are backward threaded. You learn "Righty tighty, lefty loosey" to understand normal threads. Fuel threads are the reverse of that and this is a safety feature that you don't want to violate. The converter changes the normal pipe thread into fuel threading. This should be screwed right into a propane rated flashback suppressor. This device will keep a flashback from reaching your bottle if something should go badly wrong. You can potentially skip this device but when it comes to exploding propane bottles, I prefer to play it safe. Attach the flashback suppressor to your propane fuel hose and then the other end of the fuel hose to the regulator. Screw the pressure gage on the regulator and you have the jet assembly done. Again remember to use propane sealant on all threads, if you didn't, go back and take it apart and do it right.

Burner
post-15449-0-69987500-1325552348_thumb.j post-15449-0-18234800-1325552352_thumb.j

The burner is a standard "Frosty" T burner so named after the forum user Frosty who created it and has a propensity for wrestling large trees. :)

To tap the back of the T, get a reducer that will screw into the ¾" side part and reduce it to just barely the size of the drill bit you will use for the pipe thread tap. If it is smaller, that is fine, if larger that isn't optimal. This reducer will serve as a guide to the drill to position the jet exactly in the middle of the T leg. Drill out the burner and then tap it for the ⅛" pipe that the MIG tip is attached to. Next attach the black iron pipe nipple and the ¾" to 1" reducer to act as a flare.

If you don't know how to drill and tap, then you should probably research that and practice before embarking on this project.

Now screw the burner jet into the burner and then test the burner.

Testing the Burner
post-15449-0-39939300-1325552350_thumb.j post-15449-0-11476900-1325552354_thumb.j post-15449-0-37252200-1325552356_thumb.j post-15449-0-21228500-1325552358_thumb.j post-15449-0-19021300-1325552360_thumb.j post-15449-0-94884700-1325552361_thumb.j

Check for leaks using dishwashing fluid mixed with water or, even better, child's bubble solution. If you see bubbles that is a leak. Twist it tighter, make sure you have a good amount of propane sealant and so on. Light the burner with a plumber's torch (this is the safest way to light your forge). Another great trick for checking leaks is a cheap medicine syringe used for children. Fill it with bubble fluid and squirt on your junctions. Note that while I am testing my son is sitting there with his hand on the bottle valve and watching what is going on. His job is simple, if something goes bad, he cuts the propane at the bottle.

Forge
When we say brick pile, we aren't kidding, its literally a pile of bricks on the table. Use a metal table and you can fabricate one if need be. Mine is fabricated to hold forges. Start with three bricks in the center of the table configured as shown
post-15449-0-86780700-1325552363_thumb.j

Add a hard firebrick in the middle. This will heat up in the forge and serve to regulate the forge temperature. Make sure the brick is at least the width of one brick from front, back and sides.
post-15449-0-76106500-1325552365_thumb.j

Next add vertical bricks to the side of the hard brick.
post-15449-0-73036500-1325552367_thumb.j

Now we test out the roof bricks. We want to make sure that we have the right width.
post-15449-0-42310100-1325552369_thumb.j

Now we add some hard bricks to the side to support the vertical bricks from falling. We also set up a couple of bricks to serve as the back door.
post-15449-0-24961400-1325552371_thumb.j

Now we have to drill out one brick for the flare. These bricks are very soft so be careful or you will shatter them. We use a hole saw to drill the brick. Put plywood under the brick to support it and make sure you can drill all the way through without hitting the table. When you drill, go very slow and steady. Don't press hard or the brick will shatter.
post-15449-0-09214100-1325552373_thumb.j post-15449-0-79680000-1325552374_thumb.j post-15449-0-32175000-1325552376_thumb.j post-15449-0-79180000-1325552377_thumb.j post-15449-0-98674600-1325552379_thumb.j post-15449-0-81950800-1325552381_thumb.j

Now we place the flare brick on top of the pile, stick the flare through and clamp up a support for the burner. The bricks won't be strong enough to support it.


Now we seal up the roof using a brick on edge to serve to give a roof over our front door bricks.
post-15449-0-32712700-1325552385_thumb.j post-15449-0-14503300-1325552387_thumb.j post-15449-0-84063600-1325552388_thumb.j

Finally turn on the burner to about 5psi and open the ball valve while the plumber's torch is in the forge and enjoy the glow.
post-15449-0-55717900-1325552390_thumb.j post-15449-0-25197100-1325552392_thumb.j

Enhancements:
The bricks can be coated with ITC-100 wherever they are exposed to heat. This will make the forge hold a lot more heat. You can also make a quick form the size of a brick and pour half an inch of castable over the brick (like Kastolyte 30) and then coat that with ITC-100. Make sure the first time you fire the castable you go slow. This will allow a much hotter face. You can put in blown burners, change the configuration and a dozen other enhancements.

Comments and questions are welcome.

Share this post


Link to post
Share on other sites
Thanks for the tutorial! This really helps a lot.


Glad to help. I will be adding info on how to add a 3000º hot face to a soft firebrick. Stay tuned.

Share this post


Link to post
Share on other sites

What would you call the "Metal table" that you have the forge on? I'm trying to know what to say I need on freecycle, etc.


Thanks,
Zachary

Share this post


Link to post
Share on other sites
What would you call the "Metal table" that you have the forge on? I'm trying to know what to say I need on freecycle, etc. Thanks, Zachary


Its just a generic metal table. :) Actually the one I use is one that I welded up one day. Its probably overbuilt but better than underbuilt. :)

Share this post


Link to post
Share on other sites

I used steel shelving for a while with it set up at a table height...it did not take kindly to being moved about all the time. I now use the inside frame of a trash compactor (crazy sturdy) and a folding work table that the wood top broke and I replaced the top with a piece of heavy sheet metal.

Some vinyl topped card tables are metal under the vinyl, especially the older ones. Some office tables are metal and metal topped with a "wood" insert Pull the insert and it is a rimmed steel table suitable to set a solid fuel fire pot into (and I say this in a gas forge thread HAH!) or use as you need.

Turned over drums make very nice hot tables.

One thing you can do with this fancy of a brick pile forge is use some angle iron(or shelf legs) and all-thread to build a frame to hold the bricks and burner in place so it can be moved.

Phil

Share this post


Link to post
Share on other sites

Great info, thanks for taking the time to put this together. I have a small gas forge that I bought at one point, but will be building a larger, adjustable one soon and this is a great starting point. I was actually considering going with an induction forge instead of a second gas forge, but now... :(

Share this post


Link to post
Share on other sites

That is a very good post - thank you..... AND THANK YOU VERY MUCH... "IF" you had posted a week ago before I purchased the two burner gas forge - might have saved me some money.... but who knows - I'm enjoying this one.

Thank you again.

Ken H>

Share this post


Link to post
Share on other sites

Great tutorial.

I love the idea of a reconfigurable forge, i'm in the middle of building a forge that is 1" angle with sheet steel panels, lined with fibre blanket, it has two open sides with dimensions suited to being bricked up with the soft white bricks, to change from short squat forge to long thin forge. Even to open both sides to allow odd shapes in (this is where propane forges fail compared to coke forges)

Share this post


Link to post
Share on other sites

How hot do the ouside of the insulating firebricks get? Warm or too hot to touch?

Thanks,
Zachary

Share this post


Link to post
Share on other sites
How hot do the ouside of the insulating firebricks get? Warm or too hot to touch? Thanks, Zachary


How about we put a time frame with that?

I know my forge with 2 inches of wool is rather warm but not untouchable hot after an hour, and does not seem to get much hotter by 2 hours. I don't run it much longer normally.

I have not used insulating bricks for a forge body to know.

Phil

Share this post


Link to post
Share on other sites

How hot do the ouside of the insulating firebricks get? Warm or too hot to touch?

Thanks,
Zachary


They will glow orange in some parts and those areas will be hot. Very hot. Anything near the hot face of the forge will be hot. However, on the outside you can put a gloved hand on the bricks and keep it there. Your copper hose and connections to the burner should NOT get hot. If it does, shut down the burner immediately and find whatever heat leak is allowing them to heat. The flare of the burner, on the other hand, will get red hot.

Share this post


Link to post
Share on other sites

Why do you use .025 MIG tips? Frosty says .035.


It could be .035. I try both. It depends on a lot of things. I live at almost 6000 feet of elevation so that might alter things.

Share this post


Link to post
Share on other sites

For those of you who have doubts about the abilities of a brick pile forge, check this out. I put my 3 inch ribbon burner in the brick pile and then fired it up. For laughs I put in a scrap 2" black iron end cap that was no longer usable and some scrap brass, including screws and so on. The handle I welded on broke off in the heat. When I pulled it out the metal was sparking (burning). At the same time the brass went totally molten and acumulated in the bottom of the cap but the cap itself started to bubble in the forge, turn plastic and begin to burn away or melt. That indicates an extremely high temperature.

This is the cap in the forge about 5 min after I turned off the heat and took off some bricks (with tongs).
post-15449-0-19766000-1326262692_thumb.j

I quenched it for giggles and this is all that is left of it.
post-15449-0-42267700-1326262694_thumb.j

If the brick pile forge can melt brass that easily and start to soften steel then its clearly capable of doing what 90% of beginning smiths or knife makers need to do with it.

Share this post


Link to post
Share on other sites

Great guide. I'm in the process of making a gas forge right now. The brake drum forge just wasn't cutting it. I'm thinking I might use your burner design for the new one. It'll be a two burner forge. Not sure how many cubic inches yet but bigger than your brick pile forge.

Share this post


Link to post
Share on other sites

I calculated mine to be about 230 cubic inches so a two burner should be plenty.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.