Instructables
This is a tub I built for my wife after she hurt her back at work and needed somewhere to soak and relieve tension. Our indoor tub is small and didn't work well enough for her to get any benefits of the hot water or the bath spa.

Because we have a limited budget, no truck to transport a real hot-tub, and no one to help me move such a beast, I decided building my own would be the next best thing.

I took as many pictures as I could, but the camera broke shortly after starting this and trying to salvage what few pics my phone could get, I came up with a few to get the general idea! If you have questions or comments, please leave them for me, and I'll answer them as best I can!
 
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Step 1: Step 1. Gather materials/ What you will need:


1.A stock tank- This is a 4' diameter 2' deep round stock tank I found used for $50. (You can use the plastic ones too as they are cheaper if new and easier to cut.)
2.A Chiminea/outdoor fireplace. (we had one already but they sell for around $40 new for a medium to small one at garden centers.)
3.A Bathtub Spa/Jacuzzi -
4.Two ¾ inch PVC faucets/spigots.
5.Two ¾ Male PVC adapters.
6.Four or five ¾ inch O-Rings/Washers.
7.Teflon Tape
8.JB Water Weld (for Occasional Leaks)
9.Garden Hose ½ or 5/8 inch – about 20 feet.
10.20' copper tubing (I used type L – about $25 at home improvement stores.)
11.5 to 7-¾ inch hose clamps
12.1 or 2 female hose ends.
13.Fountain Pump (I got mine at a discount store for $10 but as long as it has a 2' lift it should be fine)
14.A Piece of Plywood big enough to cover your tank (You can use other things too if you have them)
15.1 roll of electrical tape.
16. 5 or 6 pool-noodles for padding and/or insulation.(optional!)


Tools:
1.Drill with 1 inch bit or hole bit.
2.Flat head screwdriver
3.Sharp Knife
4.Jig Saw
5.Channel-Lock Pliers
6.Regular Pliers
 
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klarsen-crisp2 months ago

we dont have a copper coil, yet we are still able to use the thermo syphon method. however, we do plan on adding a copper coil to the stove pipe. in hopes that it will heat faster. as of now it takes 6 hours to go from 55 to 90... not too bad huh?

klarsen-crisp made it!2 months ago

Hey guys! :) We use this thing called a trash burner with water pipes we found on craigs list. now I'd like to insulate it. so it wont look so redneck and keep the water warm.... yall have any ideas?

CRISPSTEWW.jpgtrash burner.jpg
sdaupanner2 years ago
This might help those who are trying to bend the pipe without it crimping. Get either, a Bag of granulated sugar, or a few cans of salt ,and then fill the copper tube with either one and then bending it will put a pretty small sized loop into the copper, with out fear of a crimp. Just make sure that all of the copper tube that you are planning to bend is full of the salt or sugar otherwise it will crimp where there is none. Note to shade tree mechanics, this will also handle the bending of both brake line and fuel lines with out crimping or breaking.

better yet just fill with water an freeze it. then bend it. once its bent to shape let the ice thaw out.

Sdaupanner, that will work, but to make it work you must make sure the salt, sugar is well packed in the tube. Personally, I would use sand. That's what is used when your making a short radius bend in steel pipe. But, if you want to do a real nice job with same size loops. I would first make a mandrile out of plywood. Cut circles of plywood & screw them on top of each other, until you have a stack of them. If you use screws you can take the stack apart again easily. Straighten on end of the coil out on something hard, this way the tube will end up nice & straight. Then anchor it down on the base of stack using 2 nails side by side, on the tube will work. Then wind the tube up the stack. With this method you don't have to fill the tube with sand. I've bent tubing a lot over the years, & the only time that I had to fill it with sand was when we were bending 3" aluminium tubing making 90 degree bends on 21' lengths of tube. The sand kept the tube from cracking.
wapatterson (author) 2 years ago
I understand the concern and don't use lead based paints myself. Thanks for pointing that out though as others might use some and not know about the dangers!
Wapatterson, I was just thinking if after you cleaned & dried the tank, maybe paint it with the epoxy paint that you would use on a floor. That way I think it would protect the tank better & you wouldn't get any off spray like you would if using spray paint. Plus, the fact that the epoxy paint would make the tank take on a porceline type of finish. Just a idea.
I like your idea on the hot tub, I am with limited funds also. So I am always looking for ways to make my ideas work without spending to much cash. Plus the fact that I hardly ever throw anything away. And, if I do just that It is completely shot!

appliance spray paint then.

wapatterson (author)  kwhit1902112 years ago
Thanks!
NP
Quester552 years ago
I know your trying to save money and that is a good thing, but using the Wrong paint can be a killer. Stay away from Lead based paints of any kind, Your best bet would be a Gal. of Pool Paint and sealer.
as for your tub, so far, Great Idea. I'll have more at the end.
sconnors Quester5510 months ago
You would be hard pressed to buy lead based paint anywhere.
sconnors2 years ago
I simplified my hot tub to the extreme by putting the stove right in the tub. I made a downdraft stove from an old propane tank. I found that the water took the heat away from the steel so rapidly that there was no danger of burns from touching the stove.
wapatterson (author)  sconnors2 years ago
That is a GREAT Idea!!! I didn't think of that and I wouldn't have the equipment to cut an old propane tank to make it work, but should I ever get that I definitely will keep it in mind!
I love this ingenuity! Pics Please!!!
Easy way to cut metal is to put an abrasive blade in your skilsaw. You can also use a metal cutting blade in a reciprocating saw.
baudeagle1 year ago
Instead of placing the coiled copper tubing directly into the chiminea. Why not wrap this around the chimney? This may preserve the copper longer and would not interfere with the fire.


Could you give us a long term update? Haw has this system held up? Do you still use it?
wapatterson (author)  baudeagle1 year ago
Thanks for the suggestion but the copper pipe around the outside of the chimney would not work except if I ran the chiminea over 12 hours. The heat just would transfer enough to do anything.

As for updates I have one thing I did that improved the flow of heat, and the death of the hot-tub in general.
1. I took the copper pipe out and bent it into smaller circles, running one end in the front and the other out the top of the chimney. This greatly improved heat and flow even without the pump as more heat hit the pipe and pushed water pretty well.
2. Winter eventually killed the hot-tub, even with insulation. Getting the water up to temp and keeping it there got to be an all day event when temps got down to 40 degrees F or lower. I even added a water-bed heater under the tub and kept it at 65 degrees F to start, but the flow and the heat loss eventually killed it all.

We are in the process of moving to another state. the horse tank will probably make the trip with me. Once there I will try it again, but this time I'll be making an in-tank fire-box out of an old propane bottle. (Don't worry, it has been made safe and all flammables removed from it.) If i do that I'll post another instructable.
Attmos2 years ago
I think I would have used polyester resin. Its cheap, sandible, and non-irritating.
Amnesia Wes2 years ago
If any of you would like to see how an in-water (wood fired) heater works. Look up Snorkel Hot Tubs on google. I think they're from either Washington State or Oregon. I used to have one of their redwood hot tubs. After loading the stove and firing it up, it would take about an hour for the 6' dia., 4' deep hot tub to reach 104F. I can only imagine how long it would take for this setup to reach 104F? Maybe larger tubing will help it heat faster.
wapatterson (author)  Amnesia Wes2 years ago
That's a great share! Thank you! I might make something like that if I ever get better at welding and cutting metal. Right now I am in the process of trying out an old 7 gallon camper water heater I've salvaged. I'll post the results.

As of now, My redneck hot-tub can reach 104F within 2-3 hours if I keep a medium fire going and use the pump to push the water through. I'm working with the water heater to hopefully get rid of the pump and for better transfer of heat to water. I hope the thermo-syphon effect will increase with this new set up.
smats882 years ago
I believe cannibals call this a cooking pot!
LOL! Wonderful. Add some onions and leek, salt and pepper.

On a more serious side: what kind of care are you taking to make sure the person inside does not get electrocuted if an insulation failure occurs in the pump?
wapatterson (author)  carlos66ba2 years ago
Believe me, that was a major concern before I started with such an old pump & one not rated for higher temps!

(I guess I will edit that part to make it more clear) :)

Generally, I pull the pump before we get in. We pull it up by the cord so no reaching into the water.

That will keep the temp from climbing too high while someone soaks and the thermosyphon effect keeps it pretty average unless we turn on the bubbles.

The copper pipe boils the water then and it bubbles and gurgles but keeps the temp nice and warm while the cover is off.

The spa-pad and hose are just air so there's no electric going in the water there.

Thanks for the good question.
GOOD JOB. As for the pump I would change it to an external centrifigul pump and plug it into a GFIC outlet with a switch. They sell the pumps at Northern Tools and Harbour Freight. Electricity will bite you when you least expect it too. Love the bubble idea! That was simple and genious! I will take your cover idea one step further and add a Geo Dome to the surround deck to keep out the bugs and the heat in. This is what makes the Instructable site better than E How, ideas pass around and people come through with more ideas to improve or draw inspiration from someone elses thoughts . Thank you for sharing this. I will do the same when I get through with my project.
E-HOW i just an ad farm, that is why they care little about feedback, they will give you " instructions" on how to close a car door, pick up a rock from the ground or how to drink water from a glass as long as they can plaster ads around the page to get those advertising dollars!!!!

they are barely legal and in my opinion a waste of time...
wapatterson (author)  CHIEFGR8TWOLF2 years ago
THanks for the idea on the different pump. I will check that out once the old one gives out or I come into some cash.

The main reason I used this one is because of the limited budget I had. Had I more money there are a lot of things I'd do differently, but love the Geo-Dome idea for the bugs and heat.
What would you cover it with?
^6 milimeter clear plastic stapled to 1" framing members with a hinge on onside so it can be raised and lowered easily. Seeing where yours is located I would use 4mm black plastic on the street side for privacy. By the way those pumps that would work for your size tank would be less than $50.00.
wapatterson (author)  wapatterson2 years ago
I've added the note to the pump page- step 7 so hopefully that will be enough !

Thanks for pointing this out!
wapatterson (author)  smats882 years ago
Do you speak from experience? LOL

It would be more of a "cannibal crock-pot" since the temps don't get very hot so it'd take a long time for the cooking I guess! :P
Funny you should say that. On last nights news with Nancy Grace, is it. I hate that, babe. Anyways, it seem like a chef out in California I think, killed his wife then slow cooked her in a 55 gallon drum for 4 days. Then took her remains to the restaurant that he owned & pumped her down the drain. Wow, what do you think of that one. Like I always tell my wife, it takes all kinds of wacko's to make the world go around.
wapatterson (author)  kwhit1902112 years ago
Wow. I saw an article on that and never made the connection.

Now I am somewhat creeped out by my own design.

LOL - Just kidding. I'm gonna go warm up the tub for a soak!
Yeah, I understand. It creeped me out also. The wife was sitting along side of me at the time. She likes that news lady, ugh!! Anyways I told the wife maybe he wanted a nice tender roast to serve his customers. Hey, anymore I can only shake my head at how some people think. You watch movies on TV that are real gory. And, here's some jerk doing it in real life!!
LOL I was gonna say it reminds me of Bugs Bunny
chuckyd2 years ago
Legally sold treated lumber contains no cyanide. That was outlawed in the last century. The new stuff does contain other chemicals that are not as hazardouw as cycanide.

After having used a friend's hot tub a few years back, I highly recommend a skimmer. No matter how clean you are before entering the tub, body oils will float to the surface like pond scum.
Quester552 years ago
There are a few oversights to help you clear up.1. Us only Untreated wood in your fire, Pressure treated wood, even the old stuff, contains enough Cyanide, to put James Bond to Shame!, and those wood fumes are a killer.
2. Go to your local pool supply store and hot tub dealer or a Home Depot, for the Proper Chemicals to keep your tub germ free!
3. If you get plenty of Sun, you could try making a Solar Water Heater out of that Garden Hose, All of the info is here in Instructables.
4. Like I said, Great Idea, once I figure how to draw my Idea, and post it, I'll let you see it. for now Enjoy the fruits of your labors.
P/S, For your next project, find ROMAN Baths, on the net, those ancestors knew what they were doing.
colbaltblue2 years ago
Reminds me of a Dutch hot tub. https://www.google.com/search?q=dutch+hot+tub&hl=en&prmd=imvns&tbm=isch&tbo=u&source=univ&sa=X&ei=BfhZUL6kL-Sr2AX9toHwDg&sqi=2&ved=0CFYQsAQ&biw=1280&bih=937

If you rework the coil, you won't need the pump
wapatterson (author)  colbaltblue2 years ago
Yes, I saw that and used it for inspiration, but the problem I have is that I don't have pipe or tube that large. The 1/2" copper doesn't flow nearly enough to provide significant heating over time so the pump speeds it up quite nicely.
love your ingenuity
wapatterson (author) 2 years ago
Please note that I've added a safety tip here! Another user kindly pointed out that it was a question I left out! In short- pull the pump out before you get in!
This is AWESOME!! Thank you so much for the share!
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