Wood Gun fan bearing and door gasket questions

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Zach Hoyt

Zach Hoyt

Member
Feb 11, 2015
37
Orwell NY
We had a TARM SP140 for the first 11 years after we moved here, it rusted through at 19 years of age and was replaced in 2012 with a Wood Gun E140. We burn an average of about 20 standard cords per year. I like the WG a lot so far but there are a couple of problems I am having. One is with the fan bearing, it began to sound loud intermittently in December so I bought a spare. I tried to replace it on one of the few above-freezing days we had in January when I could shut the boiler down for a while. I stripped the threads on an old puller trying to get the fan off the shaft, then I bought a new 4 ton rated puller and could not budge it with that. I put it back together and called AHS and they recommended using a propane torch to heat the fan hub and get it to expand and pop off. If we ever have another warm day I will try this. I found a tutorial video on YouTube but the person making that video had the same problem I did. If anyone out there has actually replaced the bearing successfully and has any tips on how to do it I would be very grateful. The other thing I am wondering about is the load door gasket. It is silicone and is still in excellent shape after 2-1/2 years and 50 cords of wood but eventually it will wear out. To replace it as per the manual requires 2 days for the silicone to cure. We do not have any backup heat at this time so in the winter that would not be very handy. Is it possible to use a fiberglass rope gasket such as the lower doors have? Thank you very much for any advice. I found this forum very helpful when we were deciding what to buy to replace the TARM. I didn't join at the time but I read a number of threads.
Zach
 
Please tell me your not buring 20 cords(4X4X8) per year!!
 
muncybob said:
Please tell me your not buring 20 cords(4X4X8) per year!!
Click to expand...
I'm afraid we are. We live and work in a converted dairy barn which is about 7000 square feet and is not as insulated as would be ideal. Also I run the boiler through the summer for DHW. About a third of the wood burned in a year comes from slabs from our sawmill, the rest is cut and fetched directly from the woods. We have over 100 acres of woods which supplies firewood to the boiler and logs to the sawmill. The Wood Gun is especially nice because it takes wood up to 30 inches, which means only 2/3 as many cuts with the chainsaw when compared to wood for our old TARM which took up to 20 inches. I don't have to split nearly as much either because the door is so big, and since I split anything that has to be split by hand this is an even greater convenience. Also I can burn sawdust, shavings, the contents of the dust collector bag from the wood shop and such. The TARM only could have hardwood but this boiler will burn pine.
Zach
 
Wow, thats a lot of wood(and a lot of work!). Anyhow, I'm fairly certain the loading door will accept the same type of rope insulation as the lower doors. I apply high temp silicone over them each year, probably not really needed but I think it helps to prolong the life of the seals. I replaced the rubbery ones in my 2nd year and they still look good today.

Have not yet replaced the fan bearing so I'm no help there.
 
Zach,

That makes more sense. You are heating a SERIOUS amount of space.

Now that we are clear on that and can learn to accept your 20 annual cord, we can move along to your questions. Haha

I have not attempted my fan bearing, but generally with enough heat anything will come apart!

About that load door. I bet you COULD use fiberglass rope. The upper door sees much lower temps than the lower doors. The reason, I theorize, you get a silicone seal on the top is for longevity. As you've witnessed, it takes near forever for most of us to wear that door seal out and for me it has required very little adjustment. Normal rope seals "pack down" much more quickly.

I think a bit of preventative maintenance planning would behoove your situation. At 20 cord annual, you are probably looking at new nozzles every year, a new upper door gasket every 2-3 and a new fan bearing every 2-3 just as preventative maintenance. I'd just plan to do those in July so you don't have to worry about freezing when it's 5F outside.

ac
 
I agree with ac, do all maint. when the boiler is cold...it's no fun doing the nozzle in a hot boiler!
 
Hey Zach,

That is a lot of wood but that is also a lot of space to heat.

I think i was the guy with the video.
Yep only shot part one , because I couldn't get it off.
I heated and heated it and pulled on it and pulled on it.
I banged on it and banged on it.
I broke the jaw on a 2 jaw puller. The 3 jaw puller I had couldn't grip it right.
So I gave up.
I put it back together and it was quieter then ever.
I lost track but think I am in about 24-25 cord. Plus a few cord for DHW over the summer.
I was getting a high/low whining/humming sound.
But like I said, its nice and quiet now.

As far as a rope gasket for the load door, I'm not sure, I still have the silicone and all though it is pretty charred up, it is smooth and clean right where it makes contact with the frame.
 
avc8130 said:
I have not attempted my fan bearing, but generally with enough heat anything will come apart!
Click to expand...


That wasn't my experience.
I used the propane bottle torch I light the WG with.
Maybe that wasn't hot enough.
I didn't break out the oxy/actelyne cutting torch. But maybe that would get it hot enough.
 
When I do make the attempt again.
I will heat it up and also try this set up.
I will drill and tap the top hole to receive a 5/16" or maybe a 3/8" bolt and hopefully as I crank down on the bolt it will push the fan off.
20150212_153750.jpg
 
Mike,

When I say heat, I mean it. Oxy/Act or MAPP at the absolute minimum. Were you cherry red?

Another thing to consider is using a "cold shot" on the shaft after you get the area heated. The problem with heat is that you will most likely expand both the fan and the shaft. A quick blast with Freeze Off might shrink the shaft enough to make them pop apart.

I like that puller idea. Similar to motorcycle flywheel pullers.

ac
 
avc8130 said:
Mike,

When I say heat, I mean it. Oxy/Act or MAPP at the absolute minimum. Were you cherry red?
Click to expand...

I was using MAPP but never got it cherry
 
Thank you all very much. I guess I will have to see what happens when I try again on the bearing, but it sounds like more of a challenge than I had bargained for. The door gasket is still perfect where it touches the frame, and knowing that if I have to I can probably use rope I think I will just wait till it has a problem. I just put in my first set of replacement nozzles this winter, maybe 5-6 cords ago. I've ordered another set and they are waiting in the boiler room for when they are needed. I didn't mind changing them out in the winter, they were fast and easy and I just had to let the fire burn out and did the work with gloves and tools so I didn't burn myself. The TARM had a honeycomb brick that required fiberglass gaskets and silicone and a lot of work to replace, plus a U shaped tunnel stone on the bottom that sat up on shims of some kind of fireproof material to keep it up against the bottom of the floor, so the Wood Gun system is a great improvement as far as I am concerned. If I can get this fan business down I will be all set. Probably would be good to replace it in the summer, I called WG to ask their advice since the manual said every two years, and they said it would be OK to let it go till it began to make noise and then do it, but if I had known then what I know now about how hard it is I would have done it before winter.
Zach
 
Yesterday I ordered a fan assembly from AHS, complete from motor to fan. I will swap it onto the boiler when it comes and then I will have more leisure to try to get the fan off the shaft on the old unit. Chances are that we may end up needing a spare sometime in the life of the boiler, and we have no backup heat system so it will be good to have a spare unit on the shelf ready to bolt on.
Zach
 
Zach Hoyt said:
Yesterday I ordered a fan assembly from AHS, complete from motor to fan. I will swap it onto the boiler when it comes and then I will have more leisure to try to get the fan off the shaft on the old unit. Chances are that we may end up needing a spare sometime in the life of the boiler, and we have no backup heat system so it will be good to have a spare unit on the shelf ready to bolt on.
Zach
Click to expand...

Now you can set the whole fan assembly in a PB penetrating liquid.

Or you can get just a fan and cut the old one off.
 
Zach I replaced the bearings following AHS's 2 or 3 page instructions (with pictures) and had no problems at all! Not much more than an hour job. Do you have their instructions?
 
711mhw said:
Zach I replaced the bearings following AHS's 2 or 3 page instructions (with pictures) and had no problems at all! Not much more than an hour job. Do you have their instructions?
Click to expand...
Yes, I have the instructions in the manual, complete with photos. I just couldn't get the fan to slide off the shaft, even with a new 4 ton 2 jaw puller on it tightened down as much as I could tighten it. Once I can do it without having to worry about getting the boiler going again I'll be able to try more things: heat, candle wax, the laying on of hands, or whatever else I can think of.
Zach
 
Zach Hoyt said:
Yes, I have the instructions in the manual, complete with photos. I just couldn't get the fan to slide off the shaft, even with a new 4 ton 2 jaw puller on it tightened down as much as I could tighten it. Once I can do it without having to worry about getting the boiler going again I'll be able to try more things: heat, candle wax, the laying on of hands, or whatever else I can think of.
Zach
Click to expand...
 
I too bought an entire fan/motor assembly because I couldnt get the fan blade off.
I shot 2 subsequent videos, both with failed attempts, and this time I used my acteylen torch and got it CHERRY red. I also shot a video of the load door gasket replacement.

I still havent changed out the fan/motor assembly. I should do it before winter, but its such a quick switch Im not to worried about shutting it down when its cold out.
I think the bearing is making noise again, but I'm not totally sure. It has a high pitch whine.

Once I switch out the assembly, I will try a few more attempts to get the fan off. But in the end, it may need to be cut off.
 
When we have problems getting things apart at work, we will haul the whole assembly (whatever it is) down to the electrical motor shop down the street. Not sure how they do it, but they've never broken anything that I've brought them yet. I however, have made the mistake of not calling it quits soon enough. Customers get really cranky when you have to take their equipment out of service.
 
I changed mine a few years ago, as I recall there was a 1" fine thread nut needed that threaded onto the fan or something for the puller to grab, can't really remember. Also just used a normal bearing sourced locally, couldn't find the ceramic one AHS recommended, it is still fine.
 
I too am about to change my gasket and the 2 day cure will be a problem. I googled "speeding up RTV curing time" and found this :
Re: RTV Cure Questions | 22 June, 2000


"Most RTV's depend on atmospheric moisture to cure. You can put them in an oven with a pan of water and that will speed up the cure. I'd suggest about 150 to 180 degree F, time period to depend on the thickness of the RTV. You'll have to do some tests to see what effect this may have on the adhesive properties.

When I used to do this, we were using the RTV on larger thru hole parts on assemblies going into fighter jets, to dampen the vibrations (mid 80's)."

If the door will fit in my oven I might try it.
 
I got the new fan unit last February and put it on. It took me a couple of weeks to get the fan off the shaft of the old unit but I finally did by using an impact wrench on the 4 ton puller. The vibration seemed to help. It made a horrible screech as it came off. Just before Christmas the bearings in the new unit went bad, in fact they were louder than the original one ever got. I swapped the rebuilt original unit back on and then today I rebuilt the newer unit. I found that it was quite easy and took less than an hour. I didn't need the impact wrench. The allen head screws that hold the motor to the mounting plate were easy too, I just used a screwdriver handle with a hex tip where on the first one I had to put an allen wrench in and then beat on it with a hammer to get them loose. I don't know if things weren't as stuck on this one because it hadn't been in the boiler for as long or if the first one was just put together by a real gorilla, but it was nice to have it so much easier. If I had had this one in the first place I wouldn't have needed to buy a second fan, but it's just as well to have a backup unit.
Zach
 
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