Oxy Propane advice again please...to make sure I don't blow up

[outofthefire]

I don't remember ever having a pressure gauge on any propane bottle i've ever used. I turn it on a bit and look at the flame if I can't get a decent flame I turn the reg up, if it blows out straight away I turn it down. Once it's right I rarely touch them again, unless i'm putting a really small welding torch on then you don't need as much pressure. Going by the flame is an easier way to go

 

[[JP]]

Problem I have is not having someone that can show me what is a good flame, what's not, what happens when there's not enough pressure etc.. I'm trying to do things by the book...
I'm sure once I get the basics right then a bit of adjusting and finding out by trial and error might be alright. although I'm a bit on the back foot in regards to trial and error when things can go horribly wrong...

 

[slim_boy_fat]

you can carefully drill through the top corner & hang it on your gas bottles with some copper wire.

Then we wouldn't know if we were in the toilet or the workshop/garage or cave......

 

[outofthefire]

Problem I have is not having someone that can show me what is a good flame, what's not, what happens when there's not enough pressure etc.. I'm trying to do things by the book...
I'm sure once I get the basics right then a bit of adjusting and finding out by trial and error might be alright. although I'm a bit on the back foot in regards to trial and error when things can go horribly wrong...

If you've too much pressure on your propane it'll be hard to light because it'll keep blowing out, turning it on even a little bit. If it doesn't get hot/big enough, no matter how much you open the tap on the torch, you haven't got it turned up enough. Oxygen will be similar if it either blows out your flame or you can't get a nice sharp blue flame even with the tap turned right up.

Wind your propane reg in a bit and light your torch and then see how it's effected by opening the tap if your not happy just adjust the reg a bit and watch the flame.

 

[WorkshopChris]

Propane is easier to light with the torch and lighter up against a surface compared to in open air.

 

[[JP]]

Just revisiting this thread.... haven't had a chance yet to try out all your advice guys.
hopefully this Sunday I should have a free afternoon.. if you don't hear from me on Monday, things gone wrong! haha

 

[[JP]]

Hi all, I'm back and nothing blew up! Only today I had a chance to get in the garage as I had a day off work.
Got my jib all built up and sorted, done a few prayers, looked at all the notes I got from advice on here and turned it on! Good thing is I'm not getting the bangs now that i'm shutting oxy first, propane after. Seems to work.
I cut the oxy, then I'm left with a propane flame which then I shut off.

anyway... been a learning curve today, that's for sure!
I tried to replicate what was said here, not sure if I'm doing it well. towards the end I definitely was getting the stainless steel bar to go orange a lot quicker than at the start. I'm putting the inner cone on the material.. that seems to heat up a lot quicker.. but I'm not even sure if i'm doing it right?

i turn the propane on till just before the flame is about to separate, just before that happens. I leave the flame attached to torch.
then I add the oxy.... till the flame gets a cone shape, then when it turns a lighter blue and the start of the flame gets a bit concave, I back off to dark blue flame and cone shape, add a bit more of propane and then a bit more of oxy and off I go..

these are 2 photos... how does this cone look? and the distance I'm from my material?
actually now looking at the photo it looks pretty rubbish.

this is all I use the kit for.. bend 16mm bar to make sissy bars/ back rest for bikes I build or for friends.
definitely been a learning curve as despite my jig being symmetrical, it makes a difference the place where you apply the heat as some bends didn't come quite the same on both sides.

thanks for any advice
JP

 

[backpurge]

Glad it’s working ok, just a couple of things, you mentioned above that you are turning the oxygen off first, no the best idea, you should always turn the fuel gas off first. Also, it’s a bit hard to tell from the photo but it looks as if your oxygen might be turned up a bit high, but this could just be the photo

 

[outofthefire]

Ignore the bang that's normal and keep practising, you might be able to tie knots in your sissy bars one day no jig used either

 

[[JP]]

Glad it’s working ok, just a couple of things, you mentioned above that you are turning the oxygen off first, no the best idea, you should always turn the fuel gas off first. Also, it’s a bit hard to tell from the photo but it looks as if your oxygen might be turned up a bit high, but this could just be the photo

Well, the thing is, even on here I read about both ways of turning it off... this time I tried the different way and as I wasn't getting the bangs, then I was doing oxy first, fuel second.
but i'll do the other way around.

I tried to get a sharp defined inner cone, but can't really manage to do it, it's always kind of a blury mess.
i looked online and seen some videos where the inner flame was proper sharp blue and really small, but this was videos where they were using acetylene, so might be different with propane.

I'ts heating up though and pretty quick, but I'm not sure if I'm making good use of my gas and not using too much when I don't need to.

 

[backpurge]

You tend not to get as defined an inner cone with propane, are you using a heating or cutting nozzle

 

[[JP]]

Hi, i'm using a cutting nozzle.
it's a 3/32 nozzle, 2 piece for propane.

The reason why I'm using it is I have asked on here before and someone said the heating rosebud would use twice the ammount of gas/oxy

and seeing as I'm only heating up a very specific area, probably about 1" wide, I thought the cutting attachment would be perfect as it gives a very focused point of heat.

I also have a 1H rosebud, but never used it.

Hope it's alright to use the cutting nozzle to heat up? it's definitely doing it's job really well, but I do wonder if I'm being efficient with my gas use. but don't know anyone that uses a kit like this so they can show me. Only know people with the acetelyne kits and they tell me it's all the same (basically because they don't know the propane kits and don't want to say they don't really know for sure) .

 

[outofthefire]

Hi, i'm using a cutting nozzle.
it's a 3/32 nozzle, 2 piece for propane.

The reason why I'm using it is I have asked on here before and someone said the heating rosebud would use twice the ammount of gas/oxy

and seeing as I'm only heating up a very specific area, probably about 1" wide, I thought the cutting attachment would be perfect as it gives a very focused point of heat.

I also have a 1H rosebud, but never used it.

Hope it's alright to use the cutting nozzle to heat up? it's definitely doing it's job really well, but I do wonder if I'm being efficient with my gas use. but don't know anyone that uses a kit like this so they can show me. Only know people with the acetelyne kits and they tell me it's all the same (basically because they don't know the propane kits and don't want to say they don't really know for sure) .

You should be able to get that small blue sharp cone, you need that to cut so it's doable with oxy/propane just try backing your propane off a bit or turning your oxygen up. I use a rosebud at work for brazing and heat treating and I can do a bottle of oxygen in no time, for what your doing definitely stick with the cutting torch

 

[Turbo]

I noticed when adjusting the oxy that it goes to a sharpish inner cone but if you keep opening the oxy knob slowly the flame gets a slight yellow/orange tinge then turns back to blue but this time the inner cone is sharper.

As regards what nozzle to use to heat with, just use the smallest nozzle that gets the job done in reasonable time.

I use welding nozzles for heating a lot of the time as they give a finer flame, more precise for heating a small area. A size 25 welding tip produces a lot of heat (it's for welding 8 mm steel) and as good as a cutting nozzle but uses less gas.

 

[[JP]]

Thanks gents!! I'll give it another go.
Been in the process of beefing up my jig as with the heat the plate kinda bowed a bit and don't want that, so I've welded some angled steel down the sdes on the back of it.
also had to get a new bottle of oxygen.... :/ I only get 9L bottles at a time, might invest on size above next time. Hobbyweld is bringing out a middle size bottle, 20L for just a little more than what I pay for the 9L. but this is only my second bottle so still playing around with things.

hopefully this weekend I'll be able to test out the heating again.
Need to build another sissy bar as the one on my photo above is not to my linking.. 1 bend is not exactly the same as the opposite one and my OCD says "not good enough, keep trying" lol

 

[[JP]]

Ignore the bang that's normal and keep practising, you might be able to tie knots in your sissy bars one day no jig used either

View attachment 213271

that's pretty cool!!
ohhh I dont think i'd have be able to do it without a jig... my OCD needs the jig ahaha, I can spot things off my 1mm and can't live with it. the jigs allow me to make sure everything is exactly the same... and even then sometimes is not the same.

 

[outofthefire]

that's pretty cool!!
ohhh I dont think i'd have be able to do it without a jig... my OCD needs the jig ahaha, I can spot things off my 1mm and can't live with it. the jigs allow me to make sure everything is exactly the same... and even then sometimes is not the same.

Because it was supposed to be rope I didn't want it perfect, I would use a jig for the one your doing. On the other hand if i'd been making your sissy bar i'd have made it out of tube, I bet solid is heavy. You can fill tube with kiln dried silver sand packed in really tight and it'll bend like solid. I twisted this rope up from 3 lengths of half inch tube.

 

[[JP]]

See, I dont think the tube would be man enough to hold my stuff.. I pack a lot on it, and there's a lot of vibrations as my bikes are hardtails.
All sissy bars are made out of solid round, square, hex, so I rather keep that going. and packing the sand etc, would be a right pain if you want to make it quick.

here's a photo of what I carry, this was last year before setting off to Denmark and Sweden.

and a photo of the current one I bent, the bends near the mudguard are not exactly the same. Plus, my calculations were wrong and the diamond top worked out way too big.
although I'm making a king and queen seat for this one, I still think the top is way too big. and the camera angle makes it look bigger than what actually is.

All my previous bars were done using a cylindrical propane forge, but was a pain to use it as had to feed the rods in, then take out, put on jig, etc... that's why I gone now with the oxy kit to be easier to heat in place and bend. but it's a learning curve on this one! haha, everything is a learning curve, you never stop learning.

 

[backpurge]

Loving the bike, really sweet

 

[outofthefire]

See, I dont think the tube would be man enough to hold my stuff.. I pack a lot on it, and there's a lot of vibrations as my bikes are hardtails.
All sissy bars are made out of solid round, square, hex, so I rather keep that going. and packing the sand etc, would be a right pain if you want to make it quick.

Tube is stronger than solid, remember the rest of the bike is made out of tube, rigid or not. Silver sand pours in like water, sissy bars are only made out of solid when folk can't work tube.