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Rosebud torch


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When I switched to Oxy-Propane I changed the hoses and fittings to work per my distributor's advice. All I had to do in order to change my cutting torch was buy the appropriate tip. WHAT I'M ASKING IS: CAN I SWOP THE TIP OR DO I HAVE TO BUY ANOTHER ROSEBUD! I just needed the question answered. If all you got is a condescending response, please keep it to yourself.

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There is some difference in heat dynamics. I had a propane tip that I tried on acetylene and it disappeared in a nice pretty green flame. The local welding distributor told me that NG and propane tips will overheat on acetylene - but the reverse may not be true so you could try it and see what happens. The worst that can happen is that you'll have to buy a new tip as the torch shouldn't be harmed.

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When I switched to Oxy-Propane I changed the hoses and fittings to work per my distributor's advice. All I had to do in order to change my cutting torch was buy the appropriate tip. WHAT I'M ASKING IS: CAN I SWOP THE TIP OR DO I HAVE TO BUY ANOTHER ROSEBUD! I just needed the question answered. If all you got is a condescending response, please keep it to yourself.


Mark, I apologise if you read my response as condescending; I did not intend it as such. I realise now that my post could have been longer and less dubiously worded.

As I'm sure you're aware, there are a lot of things that can go very bad very quickly with an oxyfuel set. You did not make your question/situation very clear within the original post. A lot of people read this forum, and there is no way of telling their experience with such potentially dangerous tools (as of course with you). Making it clear that oxyacetylene sets are not designed to fit onto propane tanks could well have saved someone time, money and possibly serious maiming or even their life (as of course it could with you, had you been less prudent than you are).
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There is some difference in heat dynamics. I had a propane tip that I tried on acetylene and it disappeared in a nice pretty green flame. The local welding distributor told me that NG and propane tips will overheat on acetylene - but the reverse may not be true so you could try it and see what happens. The worst that can happen is that you'll have to buy a new tip as the torch shouldn't be harmed.


HWooldridge, you are absolutely right about that. Do not use a mixture with a faster flame front in a tip designed for a slower one (within sensible limits; I have a couple of acetylene/propane National tips, but you crank up the flow for acetylene). A couple of years ago at a CBA conference, someone connected a MAPP tank to a propane rosebud. Ran OK until it got hot enough to flashback, then BOOM. :( The tip was about the size of a D flashlight battery and cost about $200. It looked like a gun that Elmer Fudd fired without realizing that a bunny had stuffed a carrot in the end. One of the fellas said that he was sure glad that he wasn't the one who goofed the tip. I didn't get a chance to speak with the victim, but it must have been spectacular.

I heard that you could use MAPP gas in an acetylene one piece cutting tip, but propane would not work. One fellow who tried the propane confirmed this. The article also pointed out that this is only as a last resort. The use of the correct tip would save more than the cost savings from not buying another tip in pretty short order.

Since this thread was posted, I looked around on the WWW for a propane rosebud for my torch. I could only find large ones that required over 600 cfh of oxygen to operate :o. And, they are expensive. If I ever need to do larger scale heating, I will use a propane cutting torch tip. Or, a venturi burner and a pile of firebricks. I've heard that this works pretty well. As for all the other tips, they are cheap enough so that I will just buy them at the welding store. But not the rosebuds, so I understand why the question was being asked.
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I have only one acetylene rosebud. It is 3/4" in diameter and takes about 8 lbs acetylene and 15 of O2. Not enough pressure and it pops out continuously.

This is another good reason to use propane on the bigger tips as acetylene is dangerous over 15 lbs but propane can be run at higher pressure.

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You don't need a new rosebud. All you need is to make sure your regulator connection fits the propane tank and make sure that you use the correct tip. THE TORCH ITSELF CAN BE USED WITH ANY FUEL GAS!! It's just the tip and regulator connection that is different. You CAN use an acetylene tip with a LPG (Liquid Petroleum Gas), but not visa versa!!! Using acetylene gas with a LPG, it WILL overheat and potentially flash back into the tip and explode.

Pressures depend on the tip size, but it's perfectly safe to use 7-10psi of propane and 20-40psi of oxygen. just don't run the torch too long at too high of pressure because of the 1/7th rule of LPG. You shouldn't need a rosebud for long enough to worry about the rule, but here's some good reading for some same knowledge:

anvilfire.com - Gas Facts

Click on "Gas Facts"

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I am not trying to be Grinch here, but we should always go back to the manfacturers website, verify that component you are using is rated for the gas that you will be using.

There are so many variables in OX/AC OX/Propane, OX/MAPP equipment designs that we must be very careful as to what we are doing.

If you understand what you are doing (not guessing or I hope so) some flexibility could be allowed.

The flame propagation speed of actylene is much faster than that of propane.

Mapp's flame propogation speed is between actylene's and propane's

Therefore propane tips are designed to ignite the flame further back in tip so the flame will emerge fully developed.

Functionality and general safety aside if you run actylene through a MAP or propane tip it will massively overheat them as the flame is forming further back in the tip than designed because of the flame propgation speed.

Likewise if you run MAP though a propane tip it will overheat for the same reason.

Due to flame and stability issues, due again to the slower flame propagation speed, propane run through most actylene tips are non functional.

I know skunkriv and would trust his judgement that what he is doing with his rosebud is safe.

However if you are relative newbie to torches please completely play by the rules. We don't need the publicity of a blacksmith blowing up his shop (and himself)

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  • 1 month later...

The rosebud won't light. Acetylene/O2 burns twice the rate of propane, and you can't get the propane/oxygen out of the rosebud tip fast enough for it to stay lit.

You can light the rosebud with propane, no oxygen - but as soon as you turn on the oxygen, it will blow out the flame.

You're not going to get the pressure up high enough so it's useless with propane.

I don't use a propane torch to heat anything excpt glass

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  • 14 years later...
On 4/16/2008 at 2:53 AM, MilesDuvalier said:

The rosebud won't light. Acetylene/O2 burns twice the rate of propane, and you can't get the propane/oxygen out of the rosebud tip fast enough for it to stay lit.

You can light the rosebud with propane, no oxygen - but as soon as you turn on the oxygen, it will blow out the flame.

You're not going to get the pressure up high enough so it's useless with propane.

I don't use a propane torch to heat anything excpt glass

That is not correct, If I am reading your response right. if not, then i apologize. When I use my rosebud on my oxy/propane, my O2 is on about 10psi, and propane at about 3-5psi.  I light it the same as I always do. once lit, you have to turn the fuel down until it barely kisses the tip. then add Ox, then more gas, then Ox again until the little cones are close to 1/2" long.  I regularly heat 5/8" rod to bend. it takes about 20 seconds to get cherry red.  I use this setup nearly everyday in my shop. works very well.

 

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It depends on the torch. Conversion torches are getting better but . . .

I've had mine for at least 40 years now. It runs at much higher oxy psi and there's no way to tell what the propane psi is and no way to adjust it without opening the regulator. Propane is metered by the oxy psi and volume. 

Does your torch REALLY take 20 seconds to heat 5/8" rod to cherry red? You're using a brazing tip right? The heater tip (rosebud) on mine is about the size of a dime and will melt a cubic inch of steel in 13 seconds.

You adjust my torch by counting turns on the fuel and oxy valves before lighting it, then maybe a little fine tuning, depending on the work.

Does that make how you light and adjust your torch incorrect? 

Different rigs work differently.

Frosty The Lucky.

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