Rick Barter Posted June 14, 2005 Share Posted June 14, 2005 Where does one go to figure out how to correctly cut a hole in their roof, put a chimney flue in for a side-draft forge, and make it weather tight and sound so that it doesn't burn one's barn down? rvb Quote Link to comment Share on other sites More sharing options...
oakwoodforge Posted June 15, 2005 Share Posted June 15, 2005 First off: DON'T USE GALVANIZED SNAP-LOCK PIPE, IT GIVES OFF TOXIC HEAVY METAL FUMES WHEN HEATED AND IT WILL GET QUITE HOT !. Use black iron snap-lock ( like for a wood stove ) or stainless pipe( if you can afford it ). Seccond: any wall penetrations or roof penetrations should be B-vent (double wall pipe ) if going through a wall use a wall thimble and b-vent for at-least the 12-18 inches on either side of the wall or if going through a roof use atleast 48" of B-vent . Going through a wall is easier to make weather tight, all you need is the wall thimble and some silicone caulk.Rember to run you pipe a MINUMUM of 12 inches away from ANYTHING flamable this includes 2x4's insulation , drywall ... Running your vent pipe through the roof is alot more work, and if you have a flamable roof ( aspahalt shingle or cedar shake ) you should run more than the 3" standard building code minimum and use a spark arresting roof cap. Depending on your roof pich and roof construction you will need a " boot " or " roof jack " with a storm collar, there are generarly 3-4 different pitch boots availble at your local hardware store or HVAC supply house. say you have a 6/12 pitch roof on your barn ( thats 6 " rise in 12" ) you will need a 6/12 to 8/12 boot. If you have a shingle roof remove a few of the shingles in the area you will be cutting a hole in, us a 1" spoon ( wood ) bit to drill a pilot hole and break out the sawzall, be sure to cut the hole 4-6 inches larger than the B-vent , depending on the spacing of your girders. Dont forget to remove any insulaton within 12". Slip the upper edge of the roof boot up under the lip of the shingles, apply liberal amouts of butyl rubber roof sealant/adhesive and attach with those self sealing washer head roofing screws. If you have A Tin roof ( safer ) just lay out your hole. Take a sharp edged flat blade screw driver , put the edge of it on to the tin roof and bash with a good sized hammer, once you have torn a hole large enouogh to get a pair of offset tin snips in to it simply snip out your hole , be careful of sharp edges ! Apply sealant and roofing screws as above. A quick tip on puting together snap lock pipe if you haven't done it before it can be a hassel, lay the pipe on the groung seam opening upwards Kneel over it at one end start the joint by pressing the "tab" into the "notch " secure with a vise-grip continue down the pipe pressing with your thumbs, you will hear the " snap " when it is properly seated, use a few sheet metal screws to secure the joint ( away from the ends). Also if you are putting up a long run of pipe keep in mind its mutch easier to screw the joints togeter on the ground than 18' in the air standing on your tippy-toes on top a ladder( verry unsafe ). As far as A plenum ( the thing above the fire that catches the smoke ) use a steel box or 55 gallon drum cut length-wise with some angle iron legs to support it above your Forge, you can buy a "wood stove" adapter ( a square-to-round fitting that you can attach your vent pipe to) use one size larger pipe than you think necessary, for a small forge 6" is the minimum, if in a enclosed area go 8" minimum. Hope this helps! Have fun and stay safe ! incase you were wondering I used to be a Local 9 HVAC sheetmetalworker ( AKA Tinknocker ) Till my car accident. Quote Link to comment Share on other sites More sharing options...
Rick Barter Posted June 15, 2005 Author Share Posted June 15, 2005 Thanks for the great reply. Dang! I gotta read this a few more times. Can't I just use double-wall all the way up to help insulate me from all the heat too? Also, if I go through the wall instead of through the roof, won't I get a decrease in the draft? rvb Quote Link to comment Share on other sites More sharing options...
oakwoodforge Posted June 15, 2005 Share Posted June 15, 2005 Rick , of course you can use double wall b-vent all the way but 8" B-vent is more that $10.00 per foot at wholesale! If you can afford it its alot safer. Black iron woodstove pipe is less than 50 cents per foot and works great . If you go streight up through the roof the draft will be a slight bit better than going through the wall, only because you will be using two adjustable elbows ( every elbow = 6' of pipe). I don't think the minor increase in draft justifies the extra work and cost of going through the roof. Either way just be sure to run your vent Pipe 3 feet above the peak of the roof or higher if your roof is flamable. If you are venting through a wall you will have a horizontal run of pipe make run this as short as necessacary and pitch the run of pipe upwards atleast 1" rise per foot. Its been my experience that cutting a hole in a wall while I am standing on the ground or a short ladder is a whole lot easier than trying to cut through 3 layers of shingles ,Plywood decking and whatever else is under your roof while you are standing on a 30' extention ladder. Also becareful of old barn roofs they may not hold your weight ! Quote Link to comment Share on other sites More sharing options...
Rick Barter Posted June 15, 2005 Author Share Posted June 15, 2005 Wow! Great advice. My barn is about 4 years old. It's a pole barn with 6x6 posts and 2x6s, and trusses to hold up the roof. It's metal siding and metal roof. Now, how do you anchor the pipe? I know I can use bracing inside, but what about the part going up and over the roof line? Guy wires anchored to a roof truss? Thanks a ton for all your help. I can now go looking for stove pipe wholesalers. If anyone knows of any in the Kentucky area, let me know. If not, I guess I'll start with the local building supplier. Quote Link to comment Share on other sites More sharing options...
oakwoodforge Posted June 15, 2005 Share Posted June 15, 2005 Plumbers hanger strap works ok, steel cable works well too, you can use steel straping, rod stock or even angle iron, just use what ever you can get your hands on. Even if you are in a really wind prone area the round contour of the pipe resists wind-loading so extensive bracing shouldn't be required. Just be sure that every joint of pipe has at least 4 screws in it ( 5/16 hex self drilling screws are best). You should be able to get everything you need from Lowes or Home Depot , right now is the wrong season for them to carry a great selection of this stuff but with a little immagination and flexability you should be able to make something work. I just built a new built in forge in my work shop for about $85.00 including the vent just to see how $ cheap $ I could make a good one. now I use it more than my old Champion forge (I was getting tired of the hand crank anyway). The forge body is is a 9.00 X 16 Dodge Power Wagon truck wheel, the fire pot is a rear brake drum off my wife's old '96 Dodge Neon- the hole in the drum for the hub was exactly the right size for 2" gas pipe ( when you take a grinder to the threads- insert the pipe and pein the edge over to lock it in place) a 8" cast iron drain cover is my ash grate. It took ( 3) 6" long 2" gas pipe nipples ( 1) 2" tee and one end cap , I happened to have a few old electric blowers laying around and some concrete block. A rainy day trip to the local building supply house and one thing led to another... 2 hours later I was forging a new Pair of tongs with out cranking on a blower !!! ... for your side draft forge are you thinking about a long shallow fire pot or a small deep fire pot ? A peice of 2 " pipe laid on its side with enough holes drilled in it to equal the same surface area at the end opening would work, the number and size of holes would varry by the length of the desired fire pot. What are you wanting to start forging? basic tools , knives, hooks that kind of thing or are you wanting to do big stuff ? If so make your Tuyre adjustable. ... Just dont make your first project Samuri sword as you might get a little frusterated... I started making knives when I was 9,( my Step mom took away my woodcarving knife as punishment- so I decided to make one ... thank you step mom !!! ) I didn't make a respectable sword till I was 17 , I'm 28 now and still going strong. Some times the best tools are the ones you build ! Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted June 15, 2005 Share Posted June 15, 2005 Oakwood, Isn't Fairfield where Vintage Power Wagons is located? Are you acquainted with them? I have had several M37's myself but am down to only one '61 right now. Quote Link to comment Share on other sites More sharing options...
oakwoodforge Posted June 16, 2005 Share Posted June 16, 2005 You nailed me, I have probably sold you parts for your M-37's VPW is the family business :D Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted June 16, 2005 Share Posted June 16, 2005 Small world - ain't it... :D Quote Link to comment Share on other sites More sharing options...
oakwoodforge Posted June 16, 2005 Share Posted June 16, 2005 You would be surprisesd how often Flatheads and coal dust mix, I've found that Power Wagon owners from Iceland to Austraila have a higher than average ownership rate of anvils and forges. Ps: broken m-37 front axles make a mean cut-off hardy, I was working on a new one earlier tonight, A guy at the rally running 44" swampers on his m-37 striped a tracta joint in the mud down at the Adams farm I pulled the busted axles out of the scrap heap this afternoon. Sometimes I wonder what pecent of ABANA members own Power Wagons, I bet its pretty high. Quote Link to comment Share on other sites More sharing options...
Ralph Posted June 16, 2005 Share Posted June 16, 2005 All I know is I wish I could afford to get one. I love those trucks. I mean it is the perfect smithing truck..... Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted June 16, 2005 Share Posted June 16, 2005 In my life, I've owned 5 Willys Jeeps and 4 M37's. I am down to the best M37 now and plan to keep this one. Body is sound, it's completely stock with winch and runs like a top. Jeeps are fun but PW's WORK! And yes, I have bought parts from VPW... :wink: Quote Link to comment Share on other sites More sharing options...
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