Efficiency and thermal mass are two different things.
How hot do you want to get?
How fast do you want to get there?
How long do you want to be there?

I forgot.....how much do you want to spend?

Sorry, I forgot to mention water. Yes, you add water, and I believe some hydrated lime. It's been quite some time since I made this mixture so I don't remember the exact ratios.
Well, I guess what you're looking for is thermal mass more so than insulating properties. Like lining the walls with firebricks. That would definitely hold and keep temps stable once the thermal mass reaches ideal temp.

CambuiAl,

You definitely need to get the ball valve tight and sealed. If it's not too loose, you can use some hi-temperature silicone. It's usually red in color and you can get it at all automotive supply stores. A tube is about $5 here in the United States.

If you do a bit of research, you will probably find some mix recipes for the vermiculite (and possibly perlite). IIRC vermiculite is a cheep substitute used in low temp backyard forges. You might also search for lightweight cement recipes. Perlite is an expanded volcanic glass (vermiculite is an expanded silica), so not 100% which was used in which application.

Adjustable grate in my charcoal basket. 14" diameter x 12" tall

Ok...metal working noob question here...

I have two UDS that I built a coulple years ago. Currently, I use fridge magnets on the four intakes (3/4"). The magnets work great but it is time to step-up and add the nipples/ball valve. I'd also like to add the pipe up the side so I don't have to bend over everytime to adjust airflow.

My question is this...what parts do I need? What are they called?

I did search here, there and everywhere but didn't really find what I am looking for. Would like to be able to walk into Lowe's and say, "I need this..."

Thanks,

black iron pipe close nipples and lock nuts for them. I didn't use the lock nuts though, I cut my holes just right so the nipples threaded themselves into the drum creating an airtight seal.

For those that used the Big Lots grill bottom for lids, is this it?

http://m.biglots.com/mt/www.biglots....d-kettle-grill

It says 21.5 inch? Just trying to clarify

Well here is the mini-UDS I made for the place I work. Nothing flashy, just a KISS build.
http://i90.photobucket.com/albums/k2...ps1593b93d.jpg
It is a small drum, not sure of the exact size. I made this one upside down so it would be easier to clean and tend to the basket.
http://i90.photobucket.com/albums/k2...psa4694e4f.jpg
http://i90.photobucket.com/albums/k2...ps940e8e7e.jpg
http://i90.photobucket.com/albums/k2...ps130de3f6.jpg
This is the WSJ I saved at a yard sale(free).
http://i90.photobucket.com/albums/k2...psf77a7cf6.jpg
http://i90.photobucket.com/albums/k2...psf4f0cee3.jpg
http://i90.photobucket.com/albums/k2...psd36eb95c.jpg

I fired it up for a seasoning, and I'm not sure if it's the size or what. But this has been the easiest UDS I have made to control the temp. I got it up to 250, ran dead nuts for about 3 hours, bumped it up to 300 for another 2 hours, then up to 400 for a final 3 hours. Each time I had no problem hitting the temp or holding the temp. I shut it down and out of the half of bag of KBB I put in it. there is about 1/2 of that KBB left. I almost don't want to donate it to work. It's awesome.

Great handle idea/design.

I'm on page 352 and this thread is never ending. I think I got the concept, well at least by page 50 if a person doesn't get it somethings wrong :-P . This will be a great smoker to cook small quantities of meat and efficient enough to walk away. I'm getting two 125 gallon D tank's "propane" to make one hell of an offset smoker. I out grew my little charbroil offset. I don't think I can sit through and read the remaining 377 pages without climbing out of my skin screaming. Nice forum and lots of info for those like me who enjoy working with metal and cooking good grub!

Check this thing out... Igotgas came in to work today and surprised me with this early Birthday gift. He used a mule deer shed that he found up in Northern California for the handle. I know you folks have built some incredible UDS's and not to take anything away from anyone, but since this one is mine, haha I am gonna have to say it is the nicest UDS that I have ever seen.

http://i41.tinypic.com/rk3cb8.jpg

Hello everyone.

This is my first post. I'm so glad I found this forum. Such great information and inspiration. I'm about to start making my first UDS and have a question regarding sandblasting. I haven't read the whole thread yet (I cheated, by starting at page 600 or so), so hopefully my question hasn't been answered.

I see others mentioning that they've gotten theirs blasted for as little as $25. Where in the world are you finding these people? The cheapest quote I've gotten is $80. For that price, I can just about get a brand new drum. I've placed an add in Craigs List with no results. I've asked friends and no one knows anyone. Any suggestions?

If there is anyone in the Portland area reading this, and you know of someone that can do it for a decent price, please, please, let me know.

Thank you!

I finally finished assembled my third uds, stole the basket out of number 2 due to no materials on hand. I ran a breakfast fatty through her memorial weekend and let it burn through the night. Still holding 230 in the morning. Gotta love these cans...........