Heat Exchanger (wetsuit)

[omnicron]

Hey guys, I have a technical question in regards to a heat exchanger for a wetsuit. I have read many, many threads on heaters and I am considering building something like this: HOW_TO_BUILD_WET_SUIT_HEATER but I wonder if it matters on the placement of the water manifold. The one built on the iowagold site had the exhaust going through the middle of the manifold and what I'm considering is having the exhaust going around my manifold.

Hoser, I hope you catch this thread, I found a response to a post were you stated using a copper tube wrapped tightly around the exhaust pipe. How effective is this in regards to heating the water? I am going to use a 1 gallon mixing chamber to lower my risk of burning. The water was so cold that even wearing 2 wetsuits 2x7mm and floating on top of the water no matter how much weight I had on my belt, I could only stay in the water for less then 45min. Maybe I'm just a wuss, but when my boys get cold, i'm done

I plan on having the hws and a cold water line plumbed into my reservoir with ball valves so I can adjust each line (hot, cold) to get the desired output temp. I'm guessing this is how it's done. Any input is very welcome.

 

Amazon Forum Fav 👍

A History of Mining on the Kenai Peninsula, Alaska - Grab it through Amazon!

[goldhog]

I thought I had the full picture of the set up, but I don't.
I'll try and take one later.
The REASON.... for such a "cheap and silly design" for us was that we switch out engines every 5 days to service them.
So... we needed a system that simply "hooks on" to the engine and can be changed out in 3-5 minutes.
Also, it only cost about $20 - $40 to make.
A STEEL pipe, not aluminum as it will melt, slides over the exhaust.
Exhaust ports into the paint can, which contains 20 feet of coiled 1/4" copper tube.
Holes allow the exhaust to exit which you can't see.
We have a nice GATE valve to control the flow where it connects to the pump.
30' of 1/4" tubing which we covered with cheap pipe insulation as the heat loss was pretty high without that.
Comes out about 90 degrees after 30 feet of travel.
We "T" the hose at the diver so hot water goes in the front of suit as well as back.
Ours is cheap and temp, but should give you a good idea of one way to go and it has been tested.
Doc

 

[omnicron]

Thanks Doc, another idea for me to consider!
I did have a similar idea using copper tubing and a muffler shell from a riding lawn mower but the shell was to small I think, the paint can is a good idea.
The other challenge for me is I have about 30" of 1.5" exhaust pipe and a muffler for a car quieting my Subaru engine. (I like my engines quite)
This could be easy to integrate into my system if I had a paint can or something similar....
Thanks!

 

[Hoser John]

3" is the smallest wrap you can do with the copper without it squashing(wrap 30' slowly around the pipe and remove pipe so looks like a still coil). It is incased in a 4" steel pipe,wrapped for thermal retention. 1 gallon mixers works just fine. Will look for pics ,haven't had a need to use in over 6 years since new suit keeps me all warm and toasty -I'll look for pics scan/post as from old kodak camera. John

 

[omnicron]

Thank John!I don't know why i'm getting cold with two 7mm suits but then again the water temp is already 39 degrees at the 5000' elevation I'm working and when the sun is behind clouds I'm much colder.

This was my first thought to use, it came off a v-twin riding lawn mower that I scrounged from a bone yard the other week. I was going to cut it open and remove the innards and then try to coils inside but I think that maybe if I wrap the outside and then put heat tape or heat insulation over it that may work. What do you think.

 

[goldhog]

Funny... used it today mainly for testing and fine tuning.
The water flow must have slowed down due to gravels or sand.
(We have a small screen to keep line from clogging.)
Next thing I know I'm yanking it out of my suit.... HOT.....
Came up and showed Joe... steam was coming out not water.
LOL....
I take one serving of steamed butt please.

 

[omnicron]

Funny... used it today mainly for testing and fine tuning.
The water flow must have slowed down due to gravels or sand.
(We have a small screen to keep line from clogging.)
Next thing I know I'm yanking it out of my suit.... HOT.....
Came up and showed Joe... steam was coming out not water.
LOL....
I take one serving of steamed butt please.

Oh man that sucks. Hopefully you have no burns but I need to ask, do you have a mixer tank? From what I understand, the mixer tanks stop that from happening.

 

[jcazgoldchaser]

tempering valve



I have one inline with my solar to prevent scolding water from entering the house. That one's $50 from home depot.

 

[goldhog]

We'll put one on in two weeks or so, still really don't the unit right now.
But yes... it will help.

 

[Hoser John]

Yep mixer takes care a that as once ya slow down dredge the water flows slower inside the heat exchanger and gets MUCH hotter. Hence once ya stop/slow engine ya gotta increase water flow or pull the tube. A T(irrigation drip system) at the top feeds side tubes(6" or so) to arms and remainder tube goes another foot to you butt crack to warm them precious goodies down there,feet too. You get outta the water looking like the pillsbury doughboy spewing warm water from every place but ooooooooooooooooo soooooooooooooooo warm. Got a couple a lazy buds with some horrendous scars on their back as tooo lazy to utilize a mixer tank to temper temps.John

 

[omnicron]

Maybe I'm going overkill on my system, I'm going to use a 3/8" pvc airline to bring the water to a valve, 3/8" line into my suit then t off from there.
God I got a lot to do today... like put the system together and test it. Looks like I getting to go up for 4 days again, I just hope I have this system up and running.
When you say drip irrigation system, your talking about 1/8" lines right? I was going to buy some 5/16 and 3/16 plastic line and fitting...


I went up last week for what was supposed to be 4 days, ended up not leaving till the afternoon and leaving early my last day. I had issues getting my pump primed (would you believe the position of your jet inducer can effect the prime?) I usually run my jet at about the 10 o'clock position but on my first half day I decided to run at the 9 o'clock position. After a hour of trying anything to get it to prime I moved the jet back to it's normal position and it primed right away!

So with the water being cold and I having the mangina that I guess I grew, my total time in the water for those days total 9 hours. I ended up with 7 grams, I turn a profit after 2.5 grams, the time up there was still a bust.

 

[jcazgoldchaser]

5th & 6th posts:
Gold Dredge Hot water heater | Gold Dredging Forum

 

[2cmorau]

built this is one mounts to a honda 6.5 air is released from petcock valve this is the top were muffler mounts hot water runs to a tank and then to the diver

 

[Hoser John]

Need mo' bigger-went through over 4,000 pics yesterday during a deluge--nuttn'-must be in photos books and not on 'puter. WOW so much gold,sooooooooo much fun in them pics-still lookn'-John

 

[2cmorau]

like john said, another thing i learned using copper tubing make sure it's not rubbing on metal, last one wore a hole all that work shot down

 

[russau]

Ive been wanting to build a wetsuit heater for years, and ive dredged from Washington State to Georgia, and fortunatly i havent really needed one (knock on wood). i have a 3 mm full suit and a 7 mm shorty that i slip over the 3 mm if its cold enough.someday ill make one,but unfortunaly im getting old and broke down so ill probly never need one!

 

[omnicron]

My first one I put together yesterday kind of worked...If I had the cold water shut off to the mixer tank and the supply to the hws turn down to a trickle I would finally get water that was warmer. So I scrapped that and put together a manifold type. I'm putting the water manifold inside the exhaust pipe, just opposite of what the Iowagold link I posted did. I sure hope it works...I am going to try to go up today If I can get the system to work. I'm going to wrap the exhaust pipe from the head to the hws in insulation hoping that I wont lost to much heat to the air. I'll find out today.

 

[omnicron]

Oh heres a tip on bending copper.
Heat the copper up till it's red hot.
Let it COOL down. Fill the pipe with salt or find sand, taping the ends.
Once it's filled up you can bend it almost as tight as you want as long as you do it in stages.
I was able to bend 3/8 tubing around a 1.5" pipe.

 

[russau]

i was told about this method many years ago but never tried it....i have a set of small tubing benders that i use, but ive never tried todo tight bends like that.ill have to give it a try.Omnicrons idea seems the EZest and cheapest way to go!

 

[2cmorau]

I did that 3/8 tube cold wrap on 3 in exshust pipe, no sand, no heat, just slow and steadiy coiling around the pipe, i find the copper tubing gives me the better heat, but the welded pipe heater will last way longer, i run the hose down the front of my suit, only once did i have to pull the hose out cuz i felt it getting hot, i didn't clean the screens i have on the discharge end that goes to the heater. three screen are in plce foot valu hose bib and the tank