start of my rs build

the start of my rs build never built one before also a post to see how site uploads pics from pc

been getting the parts ready and i have very little money to play with





first off from a sheet to a roll via stainless steel for the burn tube i used no welding of the material but i used the copper roof folding method was fun to make

its this method of doing it


im unsure weather to do a copy of trying2hards or ppottys builds as i like to see the flames burning

the other pieces are from a steel door 4" width so just plain scrap that i intend to weld up and make the burn chamber out of as well as bending some 2" 5mm steel and welding that to it as well to create the 6" burn chamber

ive worked out the required slope to inject the heat into the burn chimney and its between 20 - 25 degrees for 4" burn flue that i have

unsure should i leave the secondary tube open fully or create it into a jet by closing the end off into a point to create more of a jet wash within the burn flue making the heat swirl faster

Hi, I'm looking forward to this build.   

gadily wrote:

unsure should i leave the secondary tube open fully or create it into a jet by closing the end off into a point to create more of a jet wash within the burn flue making the heat swirl faster

Try to create a jet wash of secondary air. One of the characteristics of rocket stoves is the fast flow of oxidizer that allows more heat from the combustion.

Interesting video, how times have changed!   Are you going to use a rolled type crimp? If so, I would be very interested in seeing how it turned out for you, SS is no fun to bend cold. :evil:

lol i did it by hand and hammer with no crimper first off with the sheet i folded about 1/2" and began rolling it with a steel pipe and hand pressure measuring it out on another piece of 4" pipe i added an extra 1" to it then cut it off then was the fun as i folded one way first 1/2" and then the other way 1/2" so it was allready at 90 degres it was closing the stainless steel that was fun to do and a vice and further bending of the steel in the right place to finally close them up enough to fold over the edge to stop the pipe expanding off then place over the anvil or vice hammer down closing it tightly the further closure was to place the stainless steel pipe against another steel pipe and hammer flat agianst the steel pipe in doing so sealing the stainless steel off

Hi, do you have any picks/video   

You know gadily this was how they made wood stoves in the old days.
I just watched a video where a guy showed an old wood stove that was made this way.

2ndburn wrote:

Hi, do you have any picks/video   

no but i can do another tube and record that via pics and video as i am use to doing that sort of method on other metals

Hi gadily that would be cool thanks,
Have you checked out:  pekka leskela  on this forum and on utube :?:

im holding off on my build at the moment due to that ive gone to direct stainless steel within the burn tube and also the vortex tube as its more on a permanent build im using ppottys first build box and internals with stainless steel 1.5mm plate or 1mm plate that ive used for the burn tube as illustrated in the pics

the burn tube is 5" x 5" x 3mm wall thickness and the vortex tube is 100mm x 2mm wall thickness both 304 stainless steel

im curious about the vortex feed tube inside the burn tube instinct is telling me to use stainless steel so ive considered using 50mm x 25mm x 1.5mm wall thickness for the vortex feed

items are being delivered at this moment and still need the stainless steel 0.8 mig wire to get as well

 
Hi, Yes I will be building the very same stove myself when the weather improves. I think 2"x1" for the secondary is big but it can always be controlled down, we can always ask ppotty1 for his opinion.  :) 
Load some vids soon ;)

heres what i have bought both are 304 descaled tubes

5x5" 3mm main burn tube stainless steel



and this 4" by 2mm stainless steel tube



its either i weld it with stainless steel mig wire or use normal wire the only thing im not sure upon is the secondary pipe inside the box shoule i use stainless steel due to the temps inside the box or use normal box steel

not forgetting i want this to last 3 years optimum usage even better if it lasts much longer than this

:suspect: 
Hi gadily,
               When steel heats up it will expand, when steel cools down it contracts. mild steel and stainless steel expand and contract at a deferent rate. Using mild steel to weld stainless steel I think the welds will eventually crack.  :(

2ndburn wrote:

:suspect: 
Hi gadily,
               When steel heats up it will expand, when steel cools down it contracts. mild steel and stainless steel expand and contract at a deferent rate. Using mild steel to weld stainless steel I think the welds will eventually crack.  :(

309L Tig or Stick rod will work well for welding Mild Carbon steel to Stainless Steel. They been doing it for years on different heating and cooling application.   

:shock:  
Hi DK,
I'm not saying you can't weld Stainless TO mild carbon steel it will be a lovely clean weld and will have nice colours and Damascus looking, nice. BUT the coefficient of expansion is different.
When a mig welder is used with mild steel wire and CO2 & 5% Argon gas mix to weld stainless steel.
And that weld is used in a situation where it is heated up and cooled down over and over in a fire box/riser for example. That weld will definitely be a 100% fail. Because the stainless will expand and shrink more than the mild steel weld will. The weld will crack at the toe of the weld.

Use an Arc welder with stainless rods or.  A Tig welder with stainless rod and pure Argon gas.

2ndburn wrote:

:shock:  
Hi DK,
I'm not saying you can't weld Stainless TO mild carbon steel it will be a lovely clean weld and will have nice colours and Damascus looking, nice. BUT the coefficient of expansion is different.
When a mig welder is used with mild steel wire and CO2 & 5% Argon gas mix to weld stainless steel.
And that weld is used in a situation where it is heated up and cooled down over and over in a fire box/riser for example. That weld will definitely be a 100% fail. Because the stainless will expand and shrink more than the mild steel weld will. The weld will crack at the toe of the weld.

Use an Arc welder with stainless rods or.  A Tig welder with stainless rod and pure Argon gas.

Hello 2ndburn,   

I am aware of the different expansion rated of unlike metals when fused together.I also know of written procedures to follow for such welding processes when necessary, to keep from weld failure.

I understand, that many of the people building there own RS are not welders or fabricators by trade. So I didn't want to over elaborate and try to make things more confusing then necessary.  

Do to the difficulties and increased changes of weld failure, I would never in courage any newbies to weld stainless steel with mig. To much can and does go wrong if your not understanding to the correct procedures to keep from weld failure during the welding process.

I was able to find a little info on weld failure that I thought might be helpful for some.              

       
http://content.lincolnelectric.com/pdfs/knowledge/articles/content/weldcracking.pdf

    
Hi DK,
 I will happily share my knowledge with anyone on this forum that is in need of help with their welding.
between the two of us all newbies to welding shouldn't have any problems.
   

dkwelder wrote:

2ndburn wrote:

:suspect: 
Hi gadily,
               When steel heats up it will expand, when steel cools down it contracts. mild steel and stainless steel expand and contract at a deferent rate. Using mild steel to weld stainless steel I think the welds will eventually crack.  :(

309L Tig or Stick rod will work well for welding Mild Carbon steel to Stainless Steel. They been doing it for years on different heating and cooling application.   

thanks for that i am aware that i need 308L or 308Lsi to weld up with stainless steel 304

as stated by yourself if welding too mild steel then id have to use 309L

as i am miging the steels up i have to consider heat as stainless isnt like mild steel and can they buckle and move with the heat

Stainless is easy to weld but very difficult to keep flat, the coefficient of linear expansion is 1.7 times that of mild steel. There isn’t much you can do about that except to weld it quickly and by doing so minimise the heat input. wrote:

the forum has a good guide on this subject

http://www.mig-welding.co.uk/stainless.htm

 :| 

ive been stalling out looking for assistance via the tests that i have done as a newbie i wasnt too sure if i had got the burn vortex right or not however i have gone with 10.3 video than the 15.3 video

https://woodstoves.forumotion.co.uk/t302-rs-vortex-testing

a little bit more work shaping the stainless steel burn pipe and a slopped vortex tube heres the start 3mm box ive cut into it so i can bend it easier by 1-1.5mm









i havent even tried with secondary air pipe yet so first off build it and weld it up then check your design without secondary air then with secondary air

 
Hi Gadily,

Looking good! your riser entrance looks a bit small, but "tack" weld it together and then do a test burn. To see if you have the vortex right.

Its easer to change if you use small tacks.

its part of the reason why i did the test burns via the other pipe and the box i made up to test openings and effects before main build of rs stove

entrance too the vortex pipe is 2 1/4" x 120mm

query thoe does the secondary air have to run in direct line or can it be run via the off shoot as im curious on the difference that it would make however i could test this while building this one up

 

Hi,
Your secondary air needs to be as hot as possible for it to relight gasses in the riser.
you don't want it cooling down.

And because hot air rises, it will work best if you put it on a slope up towards the riser.

gadily I have used regluar .035 flux core wire and have built three stoves, both having the stainless steel up riser tube welded to the mild steel firebox.

The three different stoves I have used for a full winter three years in a row, I changed the style each year.

I have not seen a single crack or any failure in the welds of all three.

Now I went a bit overboard and did over lap welds, three rows.

Now I do not know the term for that but it held up just fine.

So in theory yes failure for sure, in personal experience I have had no problems.

I will be tearing my third stove apart that I used all winter and will give a report on the weld area where the up riser tube connects to the mild steel firebox.

I plan on using some of the materials for two new stoves I will be building next.

One I plan on using next winter.

The other will be sold.

As well to note, the first two stoves showed no degradation of the steel for the riser tubes, or the firebox.

That was what I found on my first two stoves after using them for an entire winter on two different years and then taking them apart for inspection.

I believe they used to sell me 310 or 311 to weld steel to stainless.

My steel around my old stove cracked, steel on steel.
it has to do with design, not allways weld.
once you figure out how to beat the odds on that,
then you will realize, out of failures, that some were based on design only, and not weld that accually failed.

Great job on pretesting of risers. , looking forward to end video.