Post Reply 
 
Thread Rating:
  • 0 Votes - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Dry cell leaking
Author Message
cmac0351 Offline
Member
***

Posts: 149
Joined: May 2008
Reputation: 0
Post: #1
Dry cell leaking
I have been having trouble with my hose barbs leaking in the dry cell I am trying to build. I know that makes me sound like such a noob :-)

I have a tap and die set and I am using 3/8 hose barbs. I believe the MIP is listed at 1/4.

What size hole should I drill for that? Is the hole size the problem? Any other reason it might leak? I am using thread seal tape. Is there any other epoxy or thread sealer I could use?
11-03-2008 12:08 PM
Find all posts by this user Quote this message in a reply
hygear Offline
Member
***

Posts: 242
Joined: Aug 2008
Reputation: 1
Post: #2
RE: Dry cell leaking
cmac0351 Wrote:I have been having trouble with my hose barbs leaking in the dry cell I am trying to build. I know that makes me sound like such a noob :-)

I have a tap and die set and I am using 3/8 hose barbs. I believe the MIP is listed at 1/4.

What size hole should I drill for that? Is the hole size the problem? Any other reason it might leak? I am using thread seal tape. Is there any other epoxy or thread sealer I could use?

Your barb should be npt thread not mip at least the ones I bought from Lowes were.I used 5 min. epoxy to seal mine months ago and hasn't leaked a drop.I can't remember what size hole I drilled for mine,maybe some one else here knows.Or just experiment with a piece of scrap stock,thats what i did is drill it large enough for the tap to start.It not like you're tapping steel.Another tip is not to run the tap allthe way in,cut just enough that the fitting will thread in all the way,that will also insure a good tight seal.This method works well for me.

2005 Dodge Ram 1500 Quadcab 4x4 5.7 hemi
11-03-2008 12:28 PM
Find all posts by this user Quote this message in a reply
cjpeaceful Offline
Member
***

Posts: 214
Joined: Jul 2008
Reputation: 0
Post: #3
RE: Dry cell leaking
cmac0351 Wrote:I have been having trouble with my hose barbs leaking in the dry cell I am trying to build. I know that makes me sound like such a noob :-)

I have a tap and die set and I am using 3/8 hose barbs. I believe the MIP is listed at 1/4.

What size hole should I drill for that? Is the hole size the problem? Any other reason it might leak? I am using thread seal tape. Is there any other epoxy or thread sealer I could use?

For 3/8" fittings, use a 5/16" drill for the clear hole. 1/4" fittings, use a 7/16" drill bit.

What material are you using for your end plates?

Also, some tap and die sets do not have a tap for the 1/4" NPT fitting. Mine didn't and so I had to buy the tap and drill bit set from Irwin. 10.00 bucks!
11-03-2008 12:40 PM
Find all posts by this user Quote this message in a reply
cmac0351 Offline
Member
***

Posts: 149
Joined: May 2008
Reputation: 0
Post: #4
RE: Dry cell leaking
Yeah, I meant npt, my bad. I have the right one for the hose barb, 1/4" -18 NPT.

My problem must be that I drilled it with a 1/2 inch bit instead of 7/16.

I am using poly cutting boards for end caps. That brings up another question. I think I read somewhere that KOH is bad to use with poly cutting boards. Is it the same for NaOH??

cjpeaceful Wrote:
cmac0351 Wrote:I have been having trouble with my hose barbs leaking in the dry cell I am trying to build. I know that makes me sound like such a noob :-)

I have a tap and die set and I am using 3/8 hose barbs. I believe the MIP is listed at 1/4.

What size hole should I drill for that? Is the hole size the problem? Any other reason it might leak? I am using thread seal tape. Is there any other epoxy or thread sealer I could use?

For 3/8" fittings, use a 5/16" drill for the clear hole. 1/4" fittings, use a 7/16" drill bit.

What material are you using for your end plates?

Also, some tap and die sets do not have a tap for the 1/4" NPT fitting. Mine didn't and so I had to buy the tap and drill bit set from Irwin. 10.00 bucks!
11-03-2008 12:50 PM
Find all posts by this user Quote this message in a reply
cjpeaceful Offline
Member
***

Posts: 214
Joined: Jul 2008
Reputation: 0
Post: #5
RE: Dry cell leaking
Most cutting boards are at least HDPE (high density polyethylene). Some are even UHMW (which is even better). These two are resistant to most harsh chemicals - NaOH included.

Now, as far as KOH, both plastics will tolerate concentration levels of 30% or less. So, should we mix the two...I wouldn't.
11-03-2008 01:01 PM
Find all posts by this user Quote this message in a reply
mrbillr Offline
Member
***

Posts: 141
Joined: Jun 2008
Reputation: 0
Post: #6
RE: Dry cell leaking
The drill I use for 1/4 npt is 27/64. I know, it is a wierd size. But when I put the tap in the hole gauge that is what size seemed best. As was said, don't run the tap all the way down. That gives some room for the hose barb thread to seal off.
MrBill


cmac0351 Wrote:Yeah, I meant npt, my bad. I have the right one for the hose barb, 1/4" -18 NPT.

My problem must be that I drilled it with a 1/2 inch bit instead of 7/16.

I am using poly cutting boards for end caps. That brings up another question. I think I read somewhere that KOH is bad to use with poly cutting boards. Is it the same for NaOH??

cjpeaceful Wrote:
cmac0351 Wrote:I have been having trouble with my hose barbs leaking in the dry cell I am trying to build. I know that makes me sound like such a noob :-)

I have a tap and die set and I am using 3/8 hose barbs. I believe the MIP is listed at 1/4.

What size hole should I drill for that? Is the hole size the problem? Any other reason it might leak? I am using thread seal tape. Is there any other epoxy or thread sealer I could use?

For 3/8" fittings, use a 5/16" drill for the clear hole. 1/4" fittings, use a 7/16" drill bit.

What material are you using for your end plates?

Also, some tap and die sets do not have a tap for the 1/4" NPT fitting. Mine didn't and so I had to buy the tap and drill bit set from Irwin. 10.00 bucks!

MrBill
2008 f250 XLT 6.4 diesel 2x4 automatic extended cab
11-03-2008 04:01 PM
Find all posts by this user Quote this message in a reply
Gary Offline
Member
***

Posts: 1,542
Joined: Jun 2008
Reputation: 4
Post: #7
RE: Dry cell leaking
You have recieved exactly the correct information from the fellas. The only thing I can add is that the softness of HDPV allows some expansion, so shorten the tap depth a bit so the fitting will fit snugly. The drill bit size will be the same. Go nutz with tef tape, about 4-5 rounds and it'll seal well.
11-03-2008 04:29 PM
Find all posts by this user Quote this message in a reply
saltmine Offline
Member
***

Posts: 89
Joined: Aug 2008
Reputation: 0
Post: #8
RE: Dry cell leaking
After many bouts with leaks at the hose fittings, I discovered that teflon tape is probably the best thing to seal NPT threads. I've tried GOOP, silicon sealer, RTV sealer, PVC adhesive, and epoxy....Nothing seems to work as well as good 'ol teflon tape....Now, if I can just teach myself not to wrap it around the threads backward.....
11-12-2008 11:29 AM
Find all posts by this user Quote this message in a reply
Post Reply 


Forum Jump:


User(s) browsing this thread: 1 Guest(s)