Oh Crap I Broke It... Hot Blast 1500

One of the things I do now(after breaking a nub off a grate also) is use 2 hands to shake.I hold the end of the handle with my right hand and the shaft that rotates with my left.This way the nub only gets rotated and doesn't get any side to side torque.Also if I feel something get stuck in the grate I stop and pick it out with a long 3/8" x 5' poker I made.
DON

BTW I am still looking for better grates that I can modify for my furnace.Cast iron is EZ to cut and grind and what not but finding something to fit the grate holders is proving difficult.I wonder how 1" thick steel would work?

thats what me and my welding buddy are going to do. we are gonna use plate steel, something that will hold up to the heat better than cast. also, these are a two piece system. im going to fabricate the new one with a one piece system. we will keep you posted on how we do

You have the same problem I have with the Hotblast grates. I attribute it to a grate that is "cast for a price "as opposed to one cast to do its job properly. It is a realitively inexpensive furnace so I feel the improvement is reasonable. I have already broken thee nipples on grates and am finally fed up. Its not the price of the grates---its the downtime. A fabricated steel grate will be solving the problem, otherwise the Hotblast does a fantastic job.
??? Has anyone converted it to a gravity furnace eliminating the motors? How did it work? Possibly a future project for mine and looking for feedback. Thanks. Backwoodsbear in NW PA.

I took a temp reading last night of the bottom of the grate and it was around 200*.The grate holder was 450*.I guess a good grade of steel would stand up to those temps.Do any other boilers or furnaces use steel grates?
DON

I am sure steel will handle the temps. But that usually isn't the issue. Cast iron actually has a lower melting point compared to carbon steel. However cast iron will keep its shape better and not warp like carbon steel. It will probably work fine if the warping doesn't affect the performance. I attached a link with melting points of alloys.

http://www.muggyweld.com/melting.html

Coal and wood grates are almost universally made from cast iron.. it seems cast survives better in this environment.. But if you don't allow the ashpan to fill up and block air flow [cooliing air] to the bottom of the grates, then steel may hold up fairly well,, I'd design them so you can make them quickly and easily,, and keep a spare set around in case they sag too easlily from heat.

Greg L

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4 days and burning good!
Thanks to all who helped me out.
I now use the 2 hand shake method and gently is the key.
I had my grate nub welded and seems to be holding up.
I drilled and tapped the back of my front grate to hold the nub of the rear grate firm for a much improved shake.
I drilled out the center holes and ground the side slots just a bit to help the ash come through.
I now poke up through the holes and slots from the bottom after every shake. Anywhere I don't see a nice red glow.
All this seems to have improved the way this furnace runs.
I am using Reading nut and it seems to be burning down good. I have never had a clinker so I think it was more me than the coal.
Got it all piped into my main ducts over the weekend. Enjoying the cold weather and keepin warm.
The Arabs will have to keep the oil I was gonna buy this year.

thats it, that is it. I am sick of these grates. the new one came in. LASTED ONLY ONE DAY AND BROKE! I have had it. I have no idea what to do. the front is working good, but the back im poking from underneath. I can limp it along for now, but I need to do something. any suggestions would be great.

john

I don't know how thick your grates are but the only thing I know of for steel that will stand up nearly as well as cast iron in heat is stainless steel but it cant be cut with a cutting torch .I guess a plasma arc would do it if you had one big enough to do the thickness.
I cant see mild steel grates holding up long without disintergrating.
There is a place in Philadelphia I found a few years ago that cast new parts for antique cook stoves and even did the water heaters that fit down inside the cook tops for heating domestic hot water.If they are still in business I bet they.
I think I have friend that may have the address or phone number. As I recall it was operated some very old guy who only was near phone at lunch time and you had to yell but he did get my friend the parts he needed made from scratch.

Mudman, Did you temper the grate before using it? Just a thought. I got my new one and am tempering it in my coal furnace by letting it set in the ash door undrer the fire. Here is something I found on the web on tempering cast iron grates. As cheap as these us stove grates are I am sure they don't get this before shipment.

all cast iron should be seasoned before using in a normal coal or wood stove fire. This can be done two different ways. The first way is three to five small kindling fires in the stove. These fires should be small and in between each fire the stove needs to cool completely. The second way for seasoning cast iron is taking the new piece of cast iron and placing it into your oven. Starting the oven temperature at 325º and then every 30 minutes go up 25º until the oven reaches its highest temperature. (usually 500º) Do not touch the cast iron is will be HOT. Let the part cool, After all of the steps are done you are ready to start burning your stove

no I did not. I never read anywhere to season the grates like that. only read my manual which said not to start a big fire just a little one, but nothing like the steps you posted. that is really good advice, and I will now do that. thank you very much, and I hope everyone will read this that owns a hotblast. once you figure out these units they will really throw out some heat good.

Learning something new every day!
Got to love it!
And if you made it out os stainless you could use round stock.
What are your thoughts on that?

Hang in there Mudman. I know these us stoves can be temprmental but they do work well after modification. I am about half way with mine I hope. Been fired non stop for 10 days now and counting. Just got my Dwyer Mark II manometer in the mail. Guess what.....Now comes with plastic fittings to connect it to the flue pipe. I guess I will have to go shopping for some brake line fittings and connectors to hook it all up. Hoping to see improvement after setting up the baro damper.

hey charles, you are talkin about possibly making a new shaker grate system out of stainless, right? would it hold up you think better than plate steel? would have to make the nub bigger cause the one I got is too small for the handle too much slop.

I'm going to measure a 1557 in the AM, lets see what we come up with
Charles