leak

[trapper]

My central boiler has a leak again.  Last one two years ago.  My neighbor is a welder by trade.  Last time he said the medal in the firebox is getting thin.  Leaks are always by the stay pins.   He grinds away  and puts A small patch welded to the stay pin.  Has anyone welded a patch over the entire side wall of one and what would be any negative of doing it?   This furnace is about 20 years old and  I would like to keep burning wood for a couple years yet.  Makes me feel good to do it  and we heat an entrance that would otherwise be cold.  Also gets rid of the few slabs I make. Also I like the simplicity of the one I have not worried about how much wood I use..

[rusticretreater]

I just put a new bottom on a woodmaster 4400.  It had been left sitting and totally rusted out the bottom.  I went and bought a long strip of steel 4" x 20' by 1/4" and cut it into sections long enough to insure the holes were covered and it was also attached at the ends to good solid metal. I then created a template out of cardboard that matched the curve of the tank.  Then I took all the pieces to be rolled to that shape.

I beveled the edges of each strip(it would have been easier to bevel them prior to bending) and welded them into place.  The bevel is very important as it gives a groove for the welding pool to collect over the seam between plates. I was able to fashion a way for my hydraulic piston tool to push the plates to match the curve precisely, tacking one end and pressing the plate where needed, welding as I went. 

Being a lousy welder, I had several leaks. I had to go back, grind the welds down and give it another go.  I never did get rid of all the leaks, but put two quarts of boiler stop leak in it and it fully sealed after that.  I covered all the seams and welds with a high-temp silicone sealant so that it wouldn't rust.

Because I had to work on the bottom of the furnace, I tipped it on its side.  First one direction and then the other to get a good welding angle and to get water away from the welding point.  It suffered some roof damage while doing this.

If you are working inside the firebox you wont have those problems.  But it won't be fun crawling inside that furnace either.

Flat Bar Steel  - $72.50
Rolling steel to curve - $50
Welding supplies - $40-60
Black Swan sealer 2 qts - $20 plus shipping

Toss in a few grinding discs.  

[hedgerow]

Trapper  Some years back my Garn wood boiler had some bad factory welds fail. It has a 2000 gallon water storage the fire box is built around so you can get into it. When it was clean out and inspection it had several other areas that were getting thin on the fire box. I had shoulder surgery so I couldn't work on it. Had a welder come in took measurements and had a metal working place roll some 3/16 plate and he over laid several areas. Few years later I had some more factory welds fail and another leak. He over laid another thin area on my blower box. I would have to look it up but I think May it will be four years since the last repair and so far no leaks. I sure wouldn't be scared to over lay a 20 year old boiler. He did all the welding with 7018 rod on DC Pos.