My propane forge build

[portersnacks]

Hey there guys, My name is Chris, and I'm new-er to blacksmithing.

This is my first post so I figured I'd post of my newest addition to my garage. I've never had a propane forge, but city restrictions have made my "no more coal" for now decision. I am trying out a design that I saw with open end (with fire brick doors also the design in the pictures next to my build) and Frosty's T-burners.

Just a couple questions for you guys if I may. Would the "deck" or "shelf" out front benefit me any or is it more just a waste of space? I planned on adding some sort of sliding/extending rest for longer stock,....could be used as a short rest when tucked in, but I feel work space is always limited so I didn't want to leave it out. Second question is more directed at Frosty, but if anyone could answer It'd be appreciated....Would 2 x 3/4" burners suffice in this or would I benefit from 2 x 1" burners?  I can only find either a 3/4" tee or a 1" tee.......nothing 1" x 3/4" in my area and I'm trying to build on a bit of a budget. Final inside dimensions when complete will be 14"L x 8"W x 7"H.....so approx 700 cubic inches.....if I did that math right.

Much appreciated for the replies and looking forward to my future builds and projects.....and I found a use for Rail spikes....feet. lol

Cheers

Chris  

[jjhend28]

That build looks good so far, I like that "Porch" off of the front, you would be surprised how much work gets done at the front of the forge.  What are you planning on lining it with if I can ask and are you planning on doing any welds in it?  I know a bit about burners but I use forced air as they are easier to build and use less fuel while producing more heat.   

[portersnacks]

Hey JJ,

I have Kaowool to line it with, then I've got some sort of high temp fireplace castable refractory good to 2400*. Unfortunately the Kaowool I have is 4 x 1/2".....but it was free. I have 2 x 50' rolls of it....so worst case scenario if the refractory fails I only lose a 1/2" layer of Kaowool til I get a decent refractory and re line it.

As for weld temps, I am going to be starting out probably not doing forge welds or pattern welding, but it'll definitely come down the road with more experience. I'm hoping to stay away from the excess material I need for a blower style and just simple atmospheric. I'm just trying to figure out what would be the best size or what would be enough ? I have all the suppliies to make a 3/4" tee burner right now, but i just question if it'll be enough for the space. That said with the t burner design I only have either the 3/4" tees or 1" tee's I can get either, but I don't know If the 1" mght be overkill. Worst case scenario is I get 1" and just turn the regulator down. lol

Thanks again.  

By the way, I'm in Kamloops, B.C......just above you in WA. 

[jjhend28]

The kaowool is a but thin but you can't argue with free, just put a few layers in, I generally go with 2 inches of kaowool and kast o'lite 3000 as a coating, and I cast a brick for the bottom to replace every once in a while as flux will eat it up when you get into welding.  Are you going to coat some ITC 100 or some plistex or something on the inside?  I recommend doing so, it helps with fuel economy, I went from 11 minutes to forge welding temps down to 6 minutes to forge welding temps.  You don't really need much for a forced air blower, an old hair dryer is how I got started, from there it was just over the counter pipes and 3 gas fittings, less than 30$ to get it all if I am remembering right.  But to know if your T-burners are going to put out enough heat you will need to know the volume of the area you are going to be heating. I don't remember the math for that, but google will know.  Then you need to build a burner that is adequate to heat that area.  You might want to consider building 2 smaller burners for the forge to get up to the heat you need, using ball valves to turn them off and on, then you can run one burner or both depending on you needs for the project you will be working on.  And its awesome to meet a fellow smith from the PNW!

[Frosty]

Welcome aboard Portersnacks glad to have you. If you'll put your general location in the HEADER you might discover IFI members living within visiting distance. Mentioning your location in one post isn't going to stick in anyone's mind after we open a different one.

What you need and how well burners work depends on the chamber's volume and to what temp you want it heated.

I don't know where you guys live you can't find 3/4"x1" Ts they are STANDARD plumbing, virtually nobody drops a chase the same diameter as the run. If you want to hang say 4 fawcets on a wall you the run is one diameter. the Run is the pipe coming from the main supply. Every fawcet is on a chase making them the same diameter as the run would guarantee poor flow.

Every place that handles any plumbing carries "T"s with different chase to run sizes. Go to a plumbing supply and just tell them you need a "3/4"x1" "T" You want a 3/4" chase off a 1" run." Do NOT tell them what you're doing! They can NOT legally help you build home made propane burning appliances, their insurance would drop them in a heartbeat.

Rule #1. Just ask for the part. Never, NEVER tell them what you're using it for and for heaven's sake don't ask them for advice!!

If you told them you're making a propane burner they may have just mysteriously discovered there's no such part.

Figure out how much volume you will have and look at the burner rules of thumb.

Yes, the porch or shelf is an excellent feature and I have telescoping helpers on my gas forges. They're a huge help. Don't be shy about making free standing helpers, I collected a bunch of reject sigh standards from the dumpster and use the bases as helper stands. One of my best "it followed me home" scores.

I'm with Mikey about using kiln shelf for the deck in your forge for a few reasons. #1 if you buy the high alumina shelf it's resistant to fluxes. #2, being thinner it's much less a heat sink than even a split fire brick so it uses much less fuel and time to come to and maintain heat. #3 Back to thin, it's MUCH lighter so it doesn't compress the kaowool as much nor does it displace as much so your forge can have a full 2" under the deck as well for better efficiency. #4 most kiln washes are formulated to stick to kiln shelf.

Kaowool that thin is going to need rigidizer, it's not thick enough for compression to hold it in place. Neither Metricote nor Plastix has enough strength to bridge and stay on flexible forge liners like ceramic blanket so unless you rigidize the contact layer thoroughly your kiln wash isn't going to last past the first bump. Don't get all fancy or look for the "best" just buy or make some sodium silicate, AKA "water glass" and apply it to the blanket. Give the Fire contact layer special attention it needs to be strong and reasonably hard to be a competent backer for the kiln wash.

If you want to ask questions about Naturally Aspirated (NA) burners ask me or someone who uses them. There's nothing wrong with guns but it's not very useful advice in your case.

Frosty The Lucky.

[portersnacks]

Wow....so much information so far....thanks guys. 

Frosty, you kind of lost me at the rigidizer. I'll add the link below, but this is what I was planning on using as a refractory. So basically what you're saying is I in need to coat my final layer  of Kaowool (I assume 4 layers as it's half inch thick)  with this kiln wash? Or would I coat each layer? That said after the kiln wash I'd use the mentioned refractory? Also, THAT said, basically look for kiln shelf to use instead of fire brick?

Onto on the pipe fittings, yes I haven't looked into the plumbing stores and they generally don't sell to Joe public either... but I'll try and make myself sound like a pro.  Lol. The stuff I've found is at local hardware stores.  I have a few other places I can check out, but otherwise.... if my pro approach fails,  I'll need to order online I guess.  

Just a question about your burners,  the burner flare,  I've seen Bell reducers, stainless, black pipe unions used, what would you suggest? I had planned on machining a 3/4"  union down inside the end to create the 1-12% flare. And to asnwer your question the interior space will be around 650 cubic inches.... that said would 2 x 1" burners be overkill or should I stick to 2 x 3/4" burners? 

http://www.canadiantire.ca/en/home/heating-air-conditioning/fireplaces-heating-systems/firelogs-wood-pellets-firestarters/imperial-hi-temp-stove-furnace-cement-710-ml-0642704p.html?utm_campaign=bazaarvoice&utm_medium=SearchVoice&utm_source=RatingsAndReviews&utm_content=Default

THANKS again so much. Pretty stoked to learn about all this.

Cheers

Chris

 

[Frosty]

A rigidizer is to make ceramic blanket rigid, stiff and hard. Sodium silicate, water glass is a liquid of silica dissolved in sodium. When exposed to the CO2 in air it disassociates leaving a relatively solid silica shell like glass. When you wet Kaowool with sodium silicate it cures and makes the blanket rigid. This makes it more mechanically competent. If it's not rigid then things like hard coatings will just flake off when bumped, visualize dry mud on your pants, flap your pants and the clay pops off.

NO, a kiln wash is to protect the liner from the flame and chemicals in the forge. In general furnace cement is to stick bricks together, not form a high temperature barrier between fire and whatever's outside. I have no idea about that product though the 3,000f rating "SOUNDS" good. Propane is a darned chemically active and reactive fuel so the flames can do a LOT of high temp chemical erosion and I don't know how that product stacks up.

The kiln wash forms the barrier between the flame and your refractory it gets painted or troweled on AFTER the other goop is fully dried.

And no, you don't glue the plies of Kaowool together, being rigid will keep them in place. You WANT to be able to remove one layer at a time, refractory liners are a consumable, they WILL wear out and need to be replaced so don't make it hard on yourself.

You have machine tools and you're worried about finding a 3/4"x1" T? Just buy 3/4" Ts and turn the runs out on the lathe. I hope you're using the lathe to drill and tap the T, fittings and jet. I do all the steps without removing the T from the lathe only change drill bits and exchange for the taps. I HAND TURN the lathe when tapping and let the tail stock float.

Frosty The Lucky.