Help with venturi forge burner

[Tucker Shew]

Hello! I've recently purchased a venturi on amazon and i wanted to know how i can set it up. I've tried threading a pipe nipple but ended up breaking the die, so i was wondering if there was a better way of going about this or just trying again. Thanks. Here's the link to the venturi:  Link removed

[Frosty]

Welcome aboard Tucker, glad to have you. If you put your general location in the header you'll have a better chance of meeting members living within visiting distance.

Be prepared to have the link you posted removed. You are not allowed to post link to commercial sites that do not pay for the privilege.  

How did you break a pipe die? Those things are tough, they're designed to take abuse. Forget threading a piece of pipe, buy the correct length nipple at the plumbing supply. Big box stores may not have the right length but a real plumbing supply will. Do you know how long the nipple needs to be?

Did instructions come with it? That "venturi" is just one piece of a burner, did you buy the rest of the parts necessary to build it? 

Frosty The Lucky.

[Tucker Shew]

Thank you for responding. The pipe nipple is 1/4 inch by 4 inches long.

during the threading process the bottom-most blades of the die broke off.(The die i have is a cutting die not a chasing die)

The reason I'm threading this nipple is to screw it down through that top part so i can not only use as a way to get the propane into the venturi, but also as a form of oxygen control.

i was originally going to use an extended hydraulic bulkhead fitting but the only ones long enough were from the EU. I have all the other parts this is one thing that has given me the most trouble.

What my biggest question is, should i still try the pipe nipple, or is there a better way?

Thank you.

[Buzzkill]

So, the pipe you want to cut threads on is the gas input line and you also plan to use that for a threaded choke plate to spin on.  Is that correct?

There may be some threaded lamp pipe in the size you need.

 

[Frosty]

Iron pipe is neither round nor free of scale before it's coated. Do you have access to a lathe to true it up to the correct OD? If not you might be stuck with brass pipe. Buying a burner injector from the UK sort of means the parts come from the EU. No?

Heck, living where I do I'd probably have to special order a BSPP (British Standard Pipe Parallel) die for WAY more than ordering the part from the EU. It might've been cheaper to order the complete burner in kit form from Mensi, is it that much more expensive than Amazon? 

I've seen this type propane burner around and they appear to be top notch. Better than a home built for sure.

Frosty The Lucky.

 

[Mikey98118]

This looks like the MENSI High BTU Sand Casting Aluminum Venturi Burner 1"BSP outlet is a $17 cast aluminum funnel shape with a built-in saddle to mount a ¼” BSP gas tube into. The British threading can be ignored by using smaller parts, which can be held in place by crews and nuts. The aluminum casting is thick enough to make threading screws in the its wall to hold a mixing tube in place easy, and lamp thread parts will allow you to ignore the thread in the saddle; it is available through Amazon.com:

[LeeJustice]

11 hours ago, Mikey98118 said:

held in place by crews and nuts

A crew of how many Mikey?  

[ThomasPowers]

Perhaps a crew of crows; it might be stuck in their craw?

[Frosty]

Mike did specify a crew of nuts I'm thinking he's suggesting forum members, I know SOME of the gang qualify.

Frosty The Lucky.

[Tucker Shew]

On 4/5/2022 at 9:02 AM, Buzzkill said:

So, the pipe you want to cut threads on is the gas input line and you also plan to use that for a threaded choke plate to spin on.  Is that correct?

There may be some threaded lamp pipe in the size you need.

 

Exactly. I did end up find that lamp pipe on amazon, thank you very much for that one.

On 4/5/2022 at 9:42 AM, Frosty said:

 

Heck, living where I do I'd probably have to special order a BSPP (British Standard Pipe Parallel) die for WAY more than ordering the part from the EU. It might've been cheaper to order the complete burner in kit form from Mensi, is it that much more expensive than Amazon? 

 

Frosty The Lucky.

 

The only place i could find a bulkhead fitting long enough was on ebay but the fittings were from the UK and it would've cost around $40

[Tucker Shew]

My plan is to drill out the 1/4" BSP thread but drill it out large enough to fit the injector in and then just weld a nut on.

[Frosty]

If you're going to ream out the threads, Mike's option would give you an adjustable jet; depth AND alignment. Welding the nut will pull and potentially throw off jet alignment. Having the stream of propane directed as dead center straight down the mixing tube is one of the MAIN things to get right. 

Frosty The Lucky.

[Mikey98118]

It has been about one year since I bought this part and checked it all out, but I seem to remember that lamp thread fits inside of the threaded hole, without any drilling. So, lamp thread from his local hardware store, two nuts, and two flat washers should provide an adequate gas tube for a MIG contact tip gas orifice to be mounted in. But, even if I am wrong, reaming a hole larger in an aluminum part is nothing.

The desire to thread a gas tube directly into the burner's saddle only provides an opportunity to work extra hard at taking away any chance for adjustment, in case the existing threaded hole isn't drilled and threaded accurately enough to ensure that the gas orifice centered and axially true to the rest of the burner fitting.

People keep mistaking the simple way for the easy way; it ain't necessarily so.

[Frosty]

I agree, if lamp rod will work, it's the way to go. Heck, when I made my last post I forgot it was an aluminum casting which makes welding a nut to it more than challenging.

Darn things are tempting me curse it all!

Frosty The Lucky.

[Mikey98118]

Frost,

Why would you be tempted by this part? Nearly every home built burner design to become popular for the last twenty-three years will make a better flame than this can. I only bought this part, out of a wish to be thorough in what I do or don't recommend. I could only recommend this for /12" size burners, which is why I recommended holding a smaller mixing tube in it with screws. For someone who doesn't want a big hassel building a 1/2" burner, it is worthwhile; otherwise--not.

[Frosty]

Curiosity? But if you're giving it a thumbs down my curiosity is damped considerably. 

What do you feel makes it a poor/mediocre performer?

Frosty The Lucky.

[Mikey98118]

Weak flames. The sole point of a burner is to manipulate air and fuel flow to provide the hottest possible flame or flames.

[Frosty]

Yeah, the pics in the mixing tube end show a step I wasn't impressed with at all. 

I wonder why they don't die cast the aluminum injectors, they could really clean things up. Sand casting is slower and more labor intensive than using dies. You can die cast iron too but it's not as easy, easier than sand casting though. 

Of course if I were making a version I'd spin the whole burner in quantity and spot weld the structure (bridge?) to hold jet and choke plate. A couple minutes tops, not counting the bridge mount thingy.

Frosty The Lucky.

[Mikey98118]

Die casting of zinc-aluminum parts are easy. Aluminum alloys flow at about one-third higher temperatures than zinc-aluminum alloys; too high for simple die casting. Not to high for all die casting, mind. but too thigh for cheap and easy die casting.

So, the parts are sand cast, because this is appropriate for limited amounts of cast parts.

I personally am glad they are sand cast. It makes improvements on this second rate design more likely.

[Frosty]

Temperature of the melt isn't really an issue, towards the end Soderfors was die casting their anvils. 

I've been away from casting too long to have an idea how to make the core to cast a burner like these, sand or die. 

I have to concede that it's a good idea to make upgrading the design as easy and cheap as possible.

Frosty The Lucky.