Rebuilding the GreenWood

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ISeeDeadBTUs

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I'd like to get two more years outta' the green beast, at which point I think I'd feel economically satisfied. For now, nevermind what decision I'll make when I do replace the GW100.

Ok, so she sprung a leak in the iron nipple coming out of the heat HX at the front of the boiler. As I suspected, the corrosion was from the OUTSIDE IN, not from the water side.

I took the top cover off. The insulation is still stuck to the top at the moment, but I did find rust through the cover in one spot other than the HX hole. Seems that creosote is some seriously caustic compound!!

Ok, so it looks like the next step will be to remove the HX, which means ripping the back off the beast.

I'm trying to picto-document the operation, if nothing else, to aid me in remembering how the parts go back together.

http://youarehere061.vox.com/library/post/greenwood-tear-down.html

A couple of questions for the Seton/Greenfire/Green Horizon guys . . . doesn't someone make SS skins with cleaning access for these? And does anyone know if your HX is the same dimensions as my GW100?

Jimbo
 
Are you saying you do not have access to the place that needs the repair? The pictures look like you are there.

How about calling GW and asking how they would fix it. I did tour their assembly plant, they should be able to send you pictures of the sub assemblies.

What do you attribute the cause of the damage? Running a GW without a storage tank?
 
sgschwend said:
Are you saying you do not have access to the place that needs the repair? The pictures look like you are there.

How about calling GW and asking how they would fix it. I did tour their assembly plant, they should be able to send you pictures of the sub assemblies.

What do you attribute the cause of the damage? Running a GW without a storage tank?
Click to expand...

Last I heard Greenwood was belly up. I don't know if anyone is there or if the phone # even works. Has anyone tried to contact them?
 
I called GW 425.454.4700 after hours and reached a recording, the answer listed the company name as: GW recovery. Sounds like you may find someone to talk to.
 
Do you weld Jimbo?
Can't really tell for sure but it looks like a simple fix.
I'd cut out about a 6"X6" square with the nipple in the center and just weld in a new piece with a new nipple.
 
Well, looks like we could cut the nipple below the corrosion and weld on a new one. My hangup is that, if the creosote ate through the iron like that, are the steel tubes porus also, just waiting for me to knock off the wrong piece of creosote?

So, I'm headed to remove the tubes. I talked to someone that deals with a company that makes the manifolds.

Stupid question for those of you a bit smarter than I in the engineering dept . . . any reason the manifol/tubes couldn't be SS?

If you're at all interested, I aim to keep snapping pictures and updating them in the link in the original post.

Jimbo
 
Actually I would say that you have not found your problem and you are wasting your time and money.

The way the machine is made the top of the heat exchanger does not contact the fire environment, furthermore you have a failure in a weld zone, which is much thicker than anywhere else, probably 3-4 times thicker than the tubes.

My guess is that there was a leak near the failure due to an error in the stainless steel welding. GW told me they put compressed air on their heat exchanges to prove that there were no leaks. I just kept my mouth shut because I knew that was not correct but telling them that would not change their minds.

Let me pass on a recent SS weld issue I observe, the person making weld is very meticulous cleaning the materials and making sure the welder is setup correctly but he had a tiny bit of oil left in the weld zone, something like quantity made by a finger print. The weld looked good but as it cooled a small fissure developed resulting in a very, very small leak.

Don't tear your machine apart!!!!! Just fix the defect you have.
 
sgschwend said:
The way the machine is made the top of the heat exchanger does not contact the fire environment, furthermore you have a failure in a weld zone, which is much thicker than anywhere else, probably 3-4 times thicker than the tubes.
Click to expand...

I can't tell if I like the way you think, or I just like hearing about a simple, cheap fix. But . . .

There is no SS on the Green beast. And the failure was most definitly NOT in a weld. The nipple is welded to the top of the HX manifold. The nipple is what? like 7". The failure occurred right in the middle of the nipple.

But you got me thinking . . . the part of the nipple below the failure was exposed to the same elements as the failure point EXCEPT . . . the failure point of the iron nipple had contact with the top skin and whatever GW used to try to seal this gap with.

So, if the failure was because of the contact (some sort of metulrgic reaction??) maybe I should consider welding the nipple and reassembling it. Looks like to remove the tubes I will have to continue disassembling the beast more, and will probably have messed up insulation.

I would really like to install SS skins and cleaning access panels, but maybe I should just fix what I got (seeing as to how its mid September) and get one more year out of it before a major overhall (including replacing the refractory, hopefully with a sectional unit)

sgschwend said:
Don't tear your machine apart!!!!! Just fix the defect you have.
Click to expand...

Somehow I'm starting to think you are right. But I don't have previous OWB experiance. I know some guys who were used to having welds done like every other off season.

Keep the ideas coming!!

Jimbo
 
I'm trying to understand this Jimbo, where exactly is the leak?
Is the nipple leaking or the base of the nipple where it ties into the manifold?
 
How many years have you been burning so far? Just curious.
 
The greenwood hx that I seen were made with sch a106 steel pipe and regular square tubing as the manifold ends that the 106's tie into.

To me it looks exactly like the outer sheeting was making some sort of electrolysis with the nipple. The edges of the hole through the sheeting was probably not painted good and was contacting the nipple causing the damage.

How does the inside of the nipple look?

I'd say, cut the nipple below the corrosion and weld on a new nipple. I would like to cut the nipple right off and weld on a steel coupling but I don't know how the threaded joint will hold up in that environment

And when you prep for welding, grind both parts down to clean, shinny steel. Get all the pits out.
 
If it's indeed the nipple, maybe the nipple can be cut below the leak and threaded in place.
Put a threaded coupling on it and Jimbo's good to go.
 
I did take a close look at my buddy Bruce's GW this morning, here a picture of his top:

023-1.jpg



It is a two season old machine, probably has burned about 8-10 cords of softwood.

I am sorry if I came on too strong, I just hate to see you fall into more problems.

I did try and get a picture from the inside but as you know it is very black in there; we will be adding a 500 gallon reservoir to improve on the burn. After looking at your new picture the inside of Bruce's looks a lot cleaner, there is some buildup in a few places but not much, I can barely see your tubes!

Do you think you are making an acid (H2SO4 or HCL)? How about taking a sample and dissolving it in water and measuring the pH? Along with the heat the acid would tear up the steel, cast iron or even stainless.
 
If you still have good pipe inside of the panel I would do one of two things.

1. cut it off and clean it up good and weld new nipple on.
or
2. cut off and thread it and use a coupling, cut hole out bigger in the panel(OD of coupling), and next time it eats through(if you keep it that long) just replace the coupling.

I wouldn't go any deeper than I had to you might open a can of worms and end up spending a lot of money on something that sounds like you
have decided to replace before to many more years.
 
jimbo it looks like you have a lot of moisture on the in side of your skins? maybe condensation in the summer months. also it needs a good scraping on the pipes.
 
Jimbo, here is the picture of Bruce's GW Hx tubes, he says he has never cleaned his. I hope it helps, let me know if there is anything I can do to help. fyi, we have added a draft fan to this unit, it is setup to run when the damper is open.

003-14.jpg
 
Yo! Steve! You never have to worry about coming on too strong Dude ;-)

Actually, you guys are great! I am reasonably good with statistics, some code building, talking to a crowd of 100's pissed off about their taxes . . .but I'm not so good at the best way to fix sheetz sometimes . . .
but along the line of a few of you guys that have posted . . . I was thinking about having a pro (this weld job is too important to trust to a schmuck) weld a fitting on the top og the steel manifold box. . .that way the next time it corrodes through, I can just screw a new nipple on . . .

But then someone said something about re-threading the exisitng nipple below the failure point, then a coupling and another nipple . . . . Hmmm . . . .

I will wire brush, sand, grind till I have something clean so you guys can have a look at it. I will then show it to the welder and see what he thinks.

Jimbo
 
Have you called the manufacturer for Seton (Bethel Engineering)? Here's the link to their site: http://www.rohor.com/

John Galloway is the sales rep that you want to speak to. They have the removable skin's, manifolds and other parts for sale. Not sure if they'll fit the GW, but maybe it's worth a shot (since they're so similar). I've been very pleased with their customer service.

Good luck,
 
If you can shorten the nipple and re-thread it like I said before, that would be the easiest and least expensive.
If you have to weld it, instead of cutting the nipple and butt-welding a thread-one-end nipple on it, (which takes a considerable amount of skill) , an easier way would be to weld the inside of a slip-on flange to it, or weld the inside of a extra heavy weld coupling on it.
 
What I think will be a problem is having a threaded joint in the combustion area. I don't think you will have enough nipple to re-thread anyway.

Welding on a coupling, screwing in a nipple and welding is a good idea Chuck. Butt welding is a little trickier but can be done.

Best of luck.

BTW, there can't be much left to do to remove the whole hx is there? Maybe?

Would be much easier to fix.
 
I wouldn't remove the HX, because it is the first part to go together. GW had brought in the Hx/frame assembly as one unit from their subcontractor.

So how is it going with the repair? Did you ever look at the pH of the junk clinging to the pipe? My guess is that it will be low.
 
I spoke with the distributor who i bought my stove from and they informed me that GW did go belly up!!! He said another company took over all the companys assets but none of the liabilities. Which means we are screwed when it comes to the warranty they sold us!!!!!!

He did give me a list of all the subcontractors that greenwood used in building the stoves if anyone needs anything let me know.
 
Jimbo....If I remember correctly, we talked about this in early spring. I have the same problem with just one season of burning. I didn't get to the leaking stage, but do have some deterioration in the nipple. I associate it with the lack of a good seal at that point. The huffing that I got caused the seal there to break, at with point the deterioration started. I think your right on target with your statement "Seems that creosote is some seriously caustic compound!!" I personally wouldn't put a threaded joint inside the the fire box. Go with a new welded in nipple.( just my onion ) What I did with mine was cover the affected area with a good coat of high temp silicone to be the barrier between the nipple and the skin. Keep in mind that mine was just deteriorated a little bit, no hole. I covered the nipple clear down to the square header tube, and up past the top skin a couple of inches. I also replaced the top skin with 1/4 plate as to not get any more deflection when huffing. (I have a plan to eliminate that as well.) I also had a tinny bit at the inlet nipple, same scenario..................... Keep in mind that I built mine and is not a Greenwood or Seaton............Jesse
 

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Is it possible that real thin gauge nipples were used in these boilers?
 
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