how to remove the pinture of the barrel - rocket mass heater

Dear all,

We found ourselves having a weird smell while burning our Rocket Mass Heater, we don't have any smoke from within the heater as it burns perfectly horizontally and makes the normal noise. But for the first half an hour we have to exit the room as a very chemical smell is on the air, I am betting this is from the insulation container I am using in the heating riser. It was an old carburetor product container. I am thinking on getting the heat riser out of the heater on the garden and put some sheets of newspaper with diesel or kerosene on it and turn it into fire. If it does not work I think I will try to use sand paper, but I don't want to as it will be very tiring and time consuming. Another option would be to remake the whole thing using a customized metal mesh. Any ideas or advises?

thanks a lot

Carlos and Nara

Carlos : If your System was truly tight all that smell should have gone up the Chimney, It may still be true and the smell you are getting is off of the outside of the barrel!

I know I spoke to you about getting the pdf Copy $15.ooU.S>, of 'Rocket Mass Heaters' at rocket stoves.com, however i did not check as I usually do that you got
the copy, mea culpa, my fault !

For right now I want you to concentrate on going to - youtube.com/watch?v=MpCu7aG3fgl - sorry you will have to type it in ! the technique you see on the outside of the
barrel they call Clay mache' like papier mache' instead of dipping the full sheets of paper in water its a light clay slip with multiple layers of paper stuck to the outside of
the barrel to hold in the heat to burn every thing out of and off the barrel ! This will give you some thing to do to clean up your large barrel. Use what ever sections of your
stove pipe you need to use to make this happen and then re-use the stove pipe for the first Two meters as you rebuild it after your controlled burn ! Good luck !

Late note, while you are on you tube type 55 gal Pocket Rocket into the you tube Search Tool and click on, you are looking for the video that lasts 1:43, this is what you
should have learned from page 76-77 in the 'Rocket Mass Heater' book !

For the good of the Craft ! be safe, keep warm ! PYRO Logical Big AL ! - As always, your Comments / Questions are solicited and are Welcome ! A. L.

http://www.youtube.com/watch?v=MpCu7aG3fgI

Carlos and Nara: Again, let me say I'm sorry that I didn't catch that you were unaware of the need to burn off All painted barrels, I'm usually very insistent
that this step get done, regardless !

And once again my Mac that doesn't play well with others, fails and Satamax comes through again !

Carlos , by now I think you know what you have to do, make the papier' mache' layers Dipped in clay slip and thick so that the heat is held in against the barrel to
burn off all the paint on the first try, and note the extra shaping required of the stove pipe end that goes in the barrel and used to make a chimney.

If you wanted to take apart your heat riser and replace its outer shell with a metal mesh like 'hardware cloth' or the type of 'expanded metal lath' that is used in
the under layers of Stucco , then my next question would be how Did you make your Heat Riser and what are you using for insulation now ?

After practicing on the Outer barrel you can then set up the outer shell of Your Heat Riser. on bricks and shovel in some coals from your fist fire, again make your
clay mache' layers extra thick to hold in the heat and make sure you only have to do the 'burn' one time only !

Think about it this way, 75 years ago we would have done this with letters and black and white (only) pictures that we would wait 10 -days to two weeks to get
back from the developer before we could trust them to the mails. Air mail would have been erratic enough that any post master any where on the line could decide
to send it by steam ship for the safety of the mails ! Let us know how you are making out !!

For the Good of the Craft ! Be safe, keep warm ! PYRO AL - As always your comments and questions are solicited and welcome ! A. L.

Dear Allen and Samatax.

As always I am very thankful for the information you provided. We tried the process in the video but our barrel was galvanized, therefore after the burning we noticed a thin layer of "something" still there despite the fact we also thought the outer layer of whatever it was went way. Then I tried to sand paper it and ended up using the power grinder and I guess the outcome was acceptable but I guess it will rust soon. We burn some wood this morning and no smell at all therefore the smell was originated from the outside of the barrel exactly as Allen mentioned. Thanks again guys.

I posted some pictures here. Please see the other pictures I am going to post on the other issue we are following.

We are very glad to have you guys replaying on our issues.

Best wishes.

Carlos and Nara

Carlos and Nara : By the time your fire in your barrel had changed your galvanizing from shinny to dull you had changed its ability to vaporize, again we had a small
communication problem in that I'm sure that nether Satamax and I were thinking about a galvanized barrel, rather than a painted one !, If you remember, I talked
about the fact that it would be a good idea to use the first 6 feet of galvanized pipe to make the vertical chimney of your Barrel cleaning equipment ! This was the
reason why I asked you to do it that way ! See how dull the Galvanizing looks on your stovepipe in the pictures ?

Over the last Several days i have set a new personal record for not speaking clearly and for that I apologize ! If you find that you don't understand what Satamax and I
are saying, Never be afraid to ask us to explain or re-explain the part that you are having problems with !

For the good of the craft ! Be safe, keep warm ! PYRO Logical Big AL - As always your Questions and Comments are solicited and are Welcome ! A. L.

Oye! I'm speaking loud and clear

Dear Allen,

Please accept my apologies I never thought about mentioning the barrel was galvanized, I wasn't ever very sure about it. I never thought about paints and galvanization before until now.

Still, the whole information will be useful as I am trying to convince friends and neighbors to build their Rocket Heaters.

thanks a lot,

best wishes,

Carlos and Nara

Carlos and Nara : da nada ! No Worries ! Everything that you have done, but more importantly everything you re-do makes you the old professional !

There is a general rule that I always find to be true , an 'Expert' is someone from 50 miles away that no-one 'here' Knows !

For the Good of the Craft ! Be safe and warm ! PYROLOGICALLY Big AL ! - Your comments/questions are welcome here A. L.

I must say this is a very big problem, as I failed to burn the paint from my barrel.

The paint nearly all stayed.
The barrel is now unusable for a rocket... Its form is not round any more.
It has crinkled.

We put the barrel IN / over a wood fire outside.

Thanks for this very useful discussion.

Yes, its VERY important to remove all the paint / galvanization from the barrel before using it indoors.

The method Allen pointed you toward, with paper and clay, we find very effective but time-consuming. It works best with about 3/4" to 1" (1.5-2cm) of layered, damp, clay-soaked paper, to capture the heat and absorb harmful vapors until the paint/galvanized is all consumed and turned to powder. It's important to do all the surfaces, and to prop the barrel up on a few rocks or bricks so the bottom also burns at high temperature.

After this, we generally scrub the remaining powder away with wire brushes or damp sand.

About 6" of damp straw can also work if paper is not locally available.

Other methods include the grinder as shown above, or taking the barrel to a local mechanic / auto-detailer for sand-blasting.

You can also buy unpainted barrels - I would still burn a fire in them outside to ensure no oil or varnish has been used to preserve the surface.

Once the barrel is clean of paint, the surface can be protected with high-temperature woodstove enamel or engine-block paint (these come rated as high as 2000 F, but 1200 F is also fine). Or it can be oiled and 'seasoned' like a cast-iron pan, for an attractive dark, translucent finish. Weathered steel radiates heat better than polished steel, but the difference is not enough to affect performance overmuch.

With a cleaned and oiled surface, you can even cook directly on the top as a griddle.

Yours,
Erica W

Satamax- sorry, I credited Allen with your video reference. Thanks for putting the video on!

-Erica

Erica Wisner wrote:Satamax- sorry, I credited Allen with your video reference. Thanks for putting the video on!

-Erica

Nevermind Erica. Doesn't mater.

One question thought. Do you have any idea on how to burn a barrel without clay and paper? I was thinking wraping it with rockwool. So it gets very hot and burns faster.

if I was using the 6" of damp straw is that inside too? also not clay just water?

Desi Georgia : Go back and review the video, you are building a fire inside the barrel to burn of accumulated oils/paint and crap, So far the best that we have seen is
a paper mache`-ish invention called clay mache`, this should cover the whole barrel.

This is a good time to burn up any softwood or resinous wood or whole bunches of last years 'berry Canes, you want a super hot fire,where the barrel glows f red hot
under the paper/clay mache`, some spanish friends added a layer of aluminum foil shinny side in with a final layer of paper/clay mache` over it to hold it into place !
They pronounced themselves satisfied with the results, i do wonder if the steam trapped under the foil acted for the good or the bad, but I have not personally seen
the results !

The dampened straw does work well as it confines the deteriorating paint to the immediate area of the barrel, the straw stays mostly intact until the steam is driven
off and then seems to work as well as the other methods, be sure to place rocks or bricks under your barrel to allow the then bottom to burn off cleanly!

By using 2-3 lengths of pipe you also burn off the volatile portion of the zinc galvanized coating on your barrel, then the pipe changes from a shinny surface to a dull
one, the way that the remaining zinc coating is bound to the steel piping has changed on the chemical bonding level ! Hope this helps and is timely ! Big AL !

Erica Wisner wrote:... Or it can be oiled and 'seasoned' like a cast-iron pan, for an attractive dark, translucent finish.

I have thought that would be possible and practical for a whole lot of items other than cast iron skillets.

Straw did a good job and got most if it off. Thinking about torching the rest of the paint and hitting it with a wire brush before a good seasoning.

I know this is a very old thread but those seeking information will inevitably find it and use the information within.  I have just begun cleaning the paint/powder coat/whatever it is that has been applied to the outside of my barrel.  I have considered all of the various ways of burning the paint off but having some experience with paint strippers, I decided to journey down that path first.

While most paint stripping products that I have used have been very toxic and unpleasant to work with, there is a product called Citristrip that I find to be very pleasant and easy to use.

What I do is use an old paint brush and spread the Citristrip over the area I want to strip and then cover the area with a layer of plastic.  This could be a cling film like saran wrap, or a garbage bag liner that has been opened up to gain it's full square footage.  Place that over the wet Citristrip and try to smooth it out, removing as many air pockets as is reasonable.  It's ok if some air bubbles persist.   Now the best part.  Go do something fun!  Don't worry about it for 24 hours or so.  Come back when you've had a nice break and  remove the plastic film a little at a time, exposing enough of the drum to allow you to use some kind of scraper to remove the loosened paint.  An old credit card will do the trick.  Scrape off the paint as you go, trying not to expose too much of the stripper to air.  If the stripper dries out it won't work anymore and you'll have to add more to refresh it.  Soon you'll have a barrel that is mostly clean.  You can hit some spots with stripper and a scrub pad to knock off any remaining residue.  When you're done, wipe the drum down with mineral spirits and you're good to go.

For those who don't want to do this the hot, smoky way, this might just be the ticket.  Remember, it's always a good idea to wear gloves and protective eyewear when working with chemicals.

Edit 01/19/2023

I started stripping another barrel and I wanted to share a variation of the method described above.   This time I covered a portion of the barrel with the Citristrip remover, spread it out to about 1/16 to 1/8 inch thick with an old paint brush.  Then I covered the treated area with cheap paper towel and covered that in turn with plastic sheeting to hold the vapors in.  After letting it sit overnight I was delighted to find that as I peeled the paper towel back from one corner, it was taking nearly all of the layer of paint right along with it.  No scraping involved whatsoever.  The next step was to wet another paper towel in mineral spirits and wipe it all down.  I then experimented with a larger area and got even better results.  I am now convinced I could cover an entire barrel all at once like this and have the entire barrel clean in less than one hour of effort.