LineSix

Gas, dope, leaks, and questions

Recommended Posts

I'm in the process of building my first venturi forge. It'll be a simple forge based off of Michael Porter's book. The main question I have is one I can't seem to find an answer to. I read LP rated teflon tape is a no-no for pressurized gas lines. So properly rated dope paste is what I hear some people use. My question about that is do you use pipe dope on your lines? If so, do you use pipe dope on your high pressure regulator, the line coming from it, the pressure gauge on the regulator, the quick shut off valve, and the backside of your burner where the line connects? I assume the last gets a little too warm for dope to work correctly, but I want to know what you guys do anyway. My concern is dope getting the regulator, gauge, and possibly the burner all fouled up. My other concern is having a gas leak and potentially losing my shop and/or some parts that I was born with.

 

I know that it's a touchy subject, so I'll state for the record that I take full responsibility for everything that goes right or wrong in my shop and on my property. I'm only asking what you folks do for your venturi forges. I am not asking for you to tell me what to do. If you know of a resource I can use to get that information, I would greatly appreciate that as well.

 

Thanks,

Patrick

Share this post


Link to post
Share on other sites
44 minutes ago, LineSix said:

teflon tape is a no-no for pressurized gas lines.

I've used propane rated tape for years without any problems. You have to know how to apply it, so you don't get any tape in the line. I use it on all pipe threads but not on compression fittings.

BTW welcome to IFI. I always suggest reading this thread to get the best out of the forum. READ THIS FIRST

Share this post


Link to post
Share on other sites

Welcome aboard Patrick, glad to have you. If you'll put your general location in the header you might be surprised how many of the gang live within visiting distance. 

NO, do NOT put dope or tape on the regulator's tank connection, it's sealed by an O-rig and polished faces. A LITTLE smear of dope away from the end of the nipple to the regulator is fine. Shop at a HVAC supply, they have high temp gas line dope.

Just apply it to the male connector away from the end and be sure to clean everything well if you take doped fittings apart and nothing will migrate in the lines. Migration is what makes gas rated T tape a bad idea. It CAN be applied safely but paste is faster, easier and less likely to be done incorrectly by the average joe. 

I do NOT bother to seal the connections on the burners themselves as any leakage will be drawn into the burner with the combustion air. Leakage in my final supply connections and there is, a little soapy water says they leak isn't great enough to need to be tuned out and seeing as they don't have to hold pressure it's not a thing. The ONLY time there is any gas pressure on these connections is when the burner's running, they lead directly to an OPEN jet orifice. Unless you turn the gas valve on and leave the room for a while it's no hazard.

Frosty The Lucky.

Share this post


Link to post
Share on other sites

Except for sealing leaks in the burners themselves. Minor leaks between MIG tip threads and gas pipes in burners will be drawn forward into the mixing tubes of some burners without harm, but will cause backfires in Mikey burners nearly every time.

Share this post


Link to post
Share on other sites
21 hours ago, Frosty said:

NO, do NOT put dope or tape on the regulator's tank connection, it's sealed by an O-rig and polished faces. A LITTLE smear of dope away from the end of the nipple to the regulator is fine. Shop at a HVAC supply, they have high temp gas line dope.

Just apply it to the male connector away from the end and be sure to clean everything well if you take doped fittings apart and nothing will migrate in the lines. Migration is what makes gas rated T tape a bad idea. It CAN be applied safely but paste is faster, easier and less likely to be done incorrectly by the average joe.

Thank you kindly, all of you. To be honest, I was half-expecting to be scoffed at for asking these things. I read the link that Irondragon Forge & Clay, and I'm sure to find that little bit helpful about how to search for things on this forum with Google. That little tip alone will save me a lot of trouble.

 

Thank you all for what you've said this matter. I appreciate all the welcome messages.

 

Thanks,

Patrick

 

Share this post


Link to post
Share on other sites
14 hours ago, Mikey98118 said:

but will cause backfires in Mikey burners nearly every time.

Really? Now I need to make a Mikey and see what's up. 

You're welcome Patrick, our pleasure. We don't give anybody grief for honest questions though it seems like it sometimes. We just don't usually address people like they're little kids, we just calls em like we sees em. 

We're BIG on safety so any question about propane gets our attention and serious responses. Even as silly as I get I don't joke around with safety. 

If you run into problem give us a shout.

Frosty The Lucky.

Share this post


Link to post
Share on other sites

Yes, even tiny leaks between the MIG tip and gas pipe will backfire, until they are completely sealed; it's kind of a drag.

Share this post


Link to post
Share on other sites

Hmmm, I knew your burner was more sensitive than a T but . . . wow. Any idea why? We know they are THAT sensitive and to what but why?

I'll have to give this some thought. Darn weather's too cold to go out to the shop and build one. DRATS!

Frosty The Lucky.

Share this post


Link to post
Share on other sites
On 1/18/2019 at 12:45 PM, Frosty said:

Welcome aboard Patrick, glad to have you. If you'll put your general location in the header you might be surprised how many of the gang live within visiting distance. 

NO, do NOT put dope or tape on the regulator's tank connection, it's sealed by an O-rig and polished faces. A LITTLE smear of dope away from the end of the nipple to the regulator is fine. Shop at a HVAC supply, they have high temp gas line dope.

Just apply it to the male connector away from the end and be sure to clean everything well if you take doped fittings apart and nothing will migrate in the lines. Migration is what makes gas rated T tape a bad idea. It CAN be applied safely but paste is faster, easier and less likely to be done incorrectly by the average joe. 

I do NOT bother to seal the connections on the burners themselves as any leakage will be drawn into the burner with the combustion air. Leakage in my final supply connections and there is, a little soapy water says they leak isn't great enough to need to be tuned out and seeing as they don't have to hold pressure it's not a thing. The ONLY time there is any gas pressure on these connections is when the burner's running, they lead directly to an OPEN jet orifice. Unless you turn the gas valve on and leave the room for a while it's no hazard.

Frosty The Lucky.

Frosty, thanks for your input. If I have a question and it's a serious one, no matter how dumb it might seem to you "crusties," all I'm looking for is an answer. I like jokes like the other guy, but wisdom is what I'm here for.

TThat being said, thank you folks for showing me more than a few things just in this post. Hopefully that search engine trick that IronDragon Foge and Clay pointed me to woll prevent me from cluttering up these foeums with questions already answered.

Thanks again folks for your infoformation,,

Patrick

 

Quote

 

 

Share this post


Link to post
Share on other sites
On 1/18/2019 at 12:44 PM, Irondragon Forge & Clay said:

I've used propane rated tape for years without any problems. You have to know how to apply it, so you don't get any tape in the line. I use it on all pipe threads but not on compression fittings.

BTW welcome to IFI. I always suggest reading this thread to get the best out of the forum. READ THIS FIRST

I appreciate the read. I admit, ai havent read it all yet, biut that'll be done tonight. What I did read was the search engine tip via Google. Hopefully that will help me from clogging up the forums with a 100 qustions that you've already answered.

 

Thank care now,

Patrick

 

 

Share this post


Link to post
Share on other sites
5 hours ago, Frosty said:

Hmmm, I knew your burner was more sensitive than a T but . . . wow. Any idea why? We know they are THAT sensitive and to what but why?

I've never figured that out, and its even more of a drag :unsure:

Share this post


Link to post
Share on other sites

I guess I'll have to open up one of the pirated PDFs of your book and start looking more closely. It's just too darned cold in the shop to make one though. 

Frosty The Lucky.

Share this post


Link to post
Share on other sites

You should discuss updates with the author over the original design:

Use three air intakes no matter how many were used in the book on different burner sizes.

Use a schedule #80 I/8" pipe (or an equivalent size tubing) to replace the original schedule #40 pipe and brass adapter fitting; this method is a lot less hassle and gives superior performance.

I recommend stainless steel tubing instead of pipe for the mixing tube, and  a solid metal in cap, drilled out to fit the gas pipe, to replace the reducer in the original design. I bent over backward to make it easy  for newbies to find parts when writing the book, only to find out that most people prefer hustling a little more for parts in return for a cleaner looking burner.

Share this post


Link to post
Share on other sites

I'll look him up before I build one. Right now I want to take a closer look at how it's laid out. Is there any significant differences between the one in the book and what you recommend now? Besides hardware like: scd 80 rather than 40, cap rather than reducer, # of intake ports, etc. 

Does the old design have the same problem with leaks and performance?

Frosty The Lucky.

Share this post


Link to post
Share on other sites

Nope :)

Major changes created the need for a whole different burner design; it's called a Vortex burner, and uses a fan.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.