Build yer own Back Boiler.

[Markymilarky]

Hi Chaps and Happy New Year.
I have a old wood burner i got out of the freeads fer £20. whoooooppeeeeee Bargain.
I want a heat exchanger /Back Boiler for it. I have limited financial resources. Any Ideas on anything i can use or adapt that will fit the bill?
I have some 3mm thick 100mm mild steel tube and was thinking of welding a plate with a 28mm fitting in it to each end. will have a nose round the scrap yard see if i can get some box section, think i'de prefer that.
I 've seen some central heating boiler heat exchangers on e bay, they look like there 10mm or 15mm in out and im not sure i could get a good sink to the casing with one of those.
One the box section i could weld a flange and bolt it to the woodburner.
Any ideas Chaps would be great please. max spend £40
Cheers Chaps. mark

 

[Bambergaspipe]

Hi Chaps and Happy New Year.
I have a old wood burner i got out of the freeads fer £20. whoooooppeeeeee Bargain.
I want a heat exchanger /Back Boiler for it. I have limited financial resources. Any Ideas on anything i can use or adapt that will fit the bill?
I have some 3mm thick 100mm mild steel tube and was thinking of welding a plate with a 28mm fitting in it to each end. will have a nose round the scrap yard see if i can get some box section, think i'de prefer that.
I 've seen some central heating boiler heat exchangers on e bay, they look like there 10mm or 15mm in out and im not sure i could get a good sink to the casing with one of those.
One the box section i could weld a flange and bolt it to the woodburner.
Any ideas Chaps would be great please. max spend £40
Cheers Chaps. mark

Fantastic, I`d go for that, let us know how you get on, don`t be depressed if this is your only reply. I`m only bothering cause I`m ****ed...

 

[holty]

scrapheap challenge comes to mind. i love the way its down to basic engineering. go for it whats the worst that could happen

 

[holty]

ps im drunk still

 

[TicklyT]

IIRC the back boilers in Rayburn stoves were about a foot square, and 3 or 4 inches deep, welded up out of something like 3/8" mild steel.

There was an oval mud hole in the middle of one side sealed with a rope gasket, and clamped up with a bridge piece. Very useful for cleaning it out.

The inlet pipe continued through the top, finishing near the bottom of the boiler, and the outlet finished close to the top to encourage a thermosyphon.

A pressure relief valve was fitted on the outlet close to the boiler.

The boiler fitted in place of a firebrick in the back of the firebox.

With hard water, it needed removing from the stove and thoroughly cleaning and de-scaling about every 3 or 4 years.

If anything does does go wrong, there's a chance of a VERY loud BANG, and bits of 10mm steel plate travelling in several different directions at the same time, closely followed by bits of what's left of your stove, all propelled by superheated steam. Although the volume of your proposed boiler may be small, it would be plenty big enough to demolish a house if it should explode.

 

[bengasman]

keep the woodburner for burning wood, great fun.
spend the 40 quid on useful information how to increase your income.
heating water with a woodburner is not something you want to engage in if you value your health and your home.

 

[Markymilarky]

Hi Chaps.
Whhay Bamber go easy on the vodka Matey, surpriseee i got some more replies..


Cheers hickup hicup Holty

Hi Tickly T. Brillo stuff that, ill have a look at the rayburn backboiler on the net. great info thanks very mucho Matey.

Hi Ben,
I have had a woodburner with backboiler on my old house, it was brilliant for all the hot water and 7 rads. why waste it all up the chimney. I used to boil the kettle and cook on the top. never bought any wood theres so much of it in skips etc whair people are ripping there houses apart its brilliant.
I supose i just like to make everything realllllly. if i could of got the steel cheap enough ide of made the woodburner , but when one turned up at £20 ide of been nuts to make one.
Cheeeeers Chaps fer all the replies. Ill let yas know how i get on. gota build my chimney first. If you dont hear from me for a few months youll know it wasent a good idea. Keep an eye on the news, If you hear................ House destroyed in Plymouth..... Dazed soot covered owner found walking the streets chanting " I should have listened to Bengasman"............ 1"1/4 bsp fittings found as far away as Glasgow.......... Neighbour says " he was a quiet guy, always tinkering. bit of a to55er really.

Thanks Chaps. mark
Theres more to life than medication. but not if your a Pharmicist.

 

[Norcon]

Marky, had you considered several small pipes ,like rods hanging vertical on a header connected with heat resistant flexis to the primaries.
Have the header on a lever system and when the fire heats up nice glowing red, lower the rods into the hot core and the heat will thermosyphon up into the header to be pumped away as energy.
And when the red glow decreases raise the rods up again.
Never know, might increase the efficiency.

 

[Markymilarky]

Hi Norcon, Ch Ch Cheers fer that Matey.
It makes me think of a Nuclear reactor with the raising and lowering of the rods. Thank theee for the idea, I'm not sure if your serious or not but it sounds a bit complicated for what im after. I got this image in my head, my wife dressed in a fireproof suit, shes locks the door, then in slow motion makes her way towards the woodburner. Grabbing the lever she lowers the rods into the glowing reactor.
I tap on the window " what you doing luv"
" Put the bath on for ya" she replies.
hummmmm Chars Matey. mark

 

[andytheplumber]

All you need is a cast iron tank about 2 foot square, with two holes in one at the top the other at the bottom. connect one end to a pump and run your heating system, make sure you have a header tank in the loft to top up and alow for expansion. stick you fire under the cast iron tank and off you go. sorted.

 

[Markymilarky]

Hi Andy, Chars fer that.
2 probs for me there though. 1 if this tank sits on top of the woodburner (A)itll look horrible ( and the wife wont have that) and (B) I won't be able to put my kettle on the top. o and (C) would be a bit of a job making a 8" hole through the middle for the flue pipe. but apart from that it's brilliant. and I'm sure it would work fantastic. Cheers Matey.

I got my eye on some box section and am wondering if it would be ok to use 28mm brass tank connectors as the in / out on the mild steel box section. the box would be inside the fire with 2 holes in the back of the wood burner with the brass fittings sticking out.? I'm wondering if the brass will be ok with the heat or wether i should weld steel fittings to the box? I have the brass ones already and am finding it difficult to source weld on steel fittings.

I had a thought about getting a radiator the sise of the back of the woodburner and welding it all around the edge to heat sink it to the woodburner, not sure if the heatsink would be good enough but 1 up side would be it already has in out connections and a air vent at the top. am thinking the steel of the radiator might be a bit thin though. Any ideas Chaps??? cheers everyone.. mark

 

[blondini]

In all seriousness, it is essential that there is an infallible means of dissipating surplus heat. The boiler must be designed t work on gravity flow and there needs to be a permanently open gravity flow circuit connected to a radiator or a storage cylinder. A pump could fail, the power could fail, and if there were nowhere for the heat to go it really would be very dangerous.

 

[daveaf]

This site may be helpful for you to source cheap weld on steel fittings:

http://www.bes.co.uk/products/161b....ipe fittings&gclid=CM3n4uO48pcCFc0e3godGk8hCw

Steel melts at approx 2700F, where as yellow brass starts to go at about 1700F. As long as the brass is not directly in the heat source, I think it would be fine. (Just dont solder it in) The water content will keep the vessel cooled, but you do need to allow for the worst case scenario.

How about running a series of smaller pipes in an "S-Shape" Through the top of the burner just under the top plate? You could cut holes in the end plates of the burner to bring the pipes outside so any elbows etc would not be in the heat source..
Im loving the heath Robinson approach

 

[Markymilarky]

Hi Chaps, Thank's for the replies.
Hi blondini, I have taken all that on board and do appreciate what a catastrophe could arise if theres a pump failure and no whair for all that heat to go. no doubt ill be posting a few questions about that when i get near to that stage. very much appreciate your comments Thank you.

Hi Dave, Thanks for the link and info.
Looks like a good place to get the steel fittings.
Like your idea of the s shape pipe keeping the fittings outside and being 1 piece with no joins. Whhay I've got some 3mm thick 50mm mild steel tube,
I was going to make a role cage for my car with it but sold the car. my friends got a 2" pipe bender so this could be a real go-er. Cheers Dave.

Ps just bought a brand new indirect hot water tank out of the local paper for £50. whooopppeeeeee it's all coming together. cheers Chaps.. mark

 

[superlec]

TICKLYT...YOU MADE ME LAUGH WITH YOUR"IF ANYTHING DOES GO WRONG" ANSWER LAST FRIDAY 2/1/09 I LAUGHED OUT LOUD, THE WIFE THINKS IM NUTS. HAPPY NEW YEAR TO YOU,
ROB SANSOM , AKA SUPERLEC.