problems, problems, problems... need help !

[mario brito]

my HHO unit its all SS ( see picture )
the top is transparent plastic.

i use the unit itself as negative pole and a got a screw in the middle of the top for positive pole's connection.

i got 2 problems :

1 : heat is melting the top plastic ! when i connect the positive to the SS screw in the center of the top, any Amps above 5-6 will heat the SS screw and start melting the plastic !

probable solution : instead of a screw, i can put a isolated cable and seal the hole. maybe the cable will not heat so much and the cable's isolation will help.

2 : i found one interesting thing. the unit warms faster than the water inside. i believe that the reason is the same of the screw heating problem. the electric current is generating heat because of metal resistance. this means that i'm wasting lots of power to heat something that i whant cool !

solution : stop using the unit as negative pole and drill a second hole to the negative. and i don't like this solution !

any ideas ?

thanks

[Smith03Jetta]

If you are generating enough heat to melt your lid then you've got some pretty cheap plastic for a lid. Get some of the 500 degree poly stuff that porkchop is using. 5 to 6 amps should not be producing much heat at all. You've got some serious issues here.

One thing I'll tell you is that the size of the negative plate controls the electrical circuit and how much electricity it uses. Your negative plate is grossly over sized. If you switch your polarity and run a negative rod and a positive bottle then your temp will definitely come down. Right now your poor little positive rod is getting bombarded from all sides with electrons racing from the negative bottle.

If you make the bottle your positive plate then you need to put the bottle in a pvc sleeve to keep it from grounding out...

[mario brito]

that's probaly what i'm going to do. i was putting the positive inside exactly because i didn't whant to isolate the unit

thanks

[Smith03Jetta]

maybe if you switch the polarity the temp will come down and you won't have to switch lids.

[liberybell]

If I understand correctly you just have a ss bolt (is that a long 3/8" bolt?) into the water and the ss housing acting as the - plate, right?
This is only theoretically, but I believe that no matter the polarity you are going to have heat problems. The reason is because the surface sending/receiving the electrons (the bolt as positive or negative terminal) is much smaller that the surface of your housing. The bolt is acting as a bottleneck, meaning the electrons are 'packed' as they travel through the bolt finding more room as they travel through the electrolyte and into/out of the housing. It is the concentration of electrons as they travel through the bolt what is creating your heat. And that heat will occur regardless the direction that the electrons are traveling when they pass through the bolt.
It is kind like if you use a 10g wire in your positive or negative terminal and a 28g wire in the other terminal. Regardless of the polarity your 28g wire is going to get really hot really quick.

If my theory is correct (which I could be wrong) then you best approach would be to increase the surface connected to your bolt by adding some large washers or attached a plate to the bolt.

[mario brito]

thanks for the help ! i'm going to switch polarity, just to see if there's any change in temp rising but what liberybell wrote makes sence.

that means that i can not use the SS unit as a pole ( no mather + or - ) because it' will always have a big surface area difference. oh well

i'll report back

thanks for the help !

[justaguy]

Also, the SS container will contain the heat.

[1973dodger]

Mario, I, like you have had this problem with stainless steel terminals and leads going to my cell outside of the water and have swapped over to copper wire to go to my terminals from the cell and have sealed any contact points of the wire and terminal not covered by insulation so no electrolyte can get to them. Actually the electrolyte has little effect on the wire , it is the oxygen attracted to the positive, that is culprit in attacking the copper. I know this is not what is suggested by most, but my heating issues have stopped. Stainless is a sorry conductor and unless it is in the electrolyte bath it is going to heat up due to resistence with any major load. Just my 2 cents worth.

1973 dodger

[Johnh]

Stainless bolts are not very good conductors. I have switched to nickel plated copper bolts for all my connections, you can get them from a commercial electrical supply company or a place that makes commercial switchgear and control panels. They work great. Plain copper bolts are also OK but I didnt like the green look . They seem to last OK.
John

[mario brito]

thanks all of you for helping and giving ideas and solutions

i'm going to make some modifications and report back

initially i thought that a SS container would be the best choice, but now i'm not so sure about that. still, even if it fails all the way, experience DOES matters ! and it could turn out to be a "don't go this way"

thanks