Looking for source for SS tubing for exhaust elbows

[Nick F]

I am going to make new exhaust elbows and need a small quantity of thin wall SS tubing (actually Schedule 10 pipe, 2-1/2 and 3 inch sizes, 316SS).

I will buy the materials and work with a welder to make the elbows.

Any suggestions on where to buy pipe online. I have found butt-weld elbows for a reasonable price, but not cut pipe.

 

[twistedtree]

McMaster?

 

[AnsleyS]

Why don't you look at the fiberglass elbows.

 

[Almad]

Hey Nick. I’m with AnsleyS on that one. Recently in a small remote town and neede to replace 6” elbows. S/s not an easy option. So got some 6” plumbers pipe and wrapped it in fiberglass using vynlester resin. Cut it up to desired shape and wrapped again. Bingo. 2 years later and still going strong. Also inexpensive.

 

[Bmarler]

If McMaster doesn’t have what you want, try online metals, or Alaska copper and brass.
Both will have most standard sizes in stock and will cut to length.

 

[DennisB1]

If you are using 316 as. Use 316l which is a low carbon version which will reduce problems in the heat affected zone when you weld. Alaska copper should have what you want.

 

[AnsleyS]

Look at these:


https://www.westmarine.com/centek-45-vernatube-exhaust-elbows-P006_180_005_002.html

 

[Nick F]

If McMaster doesn’t have what you want, try online metals, or Alaska copper and brass.
Both will have most standard sizes in stock and will cut to length.

Thanks for this - Alaskan was a good tip - they have an impressive selection of options other than the standard sched 10 pipe size. I have not seen pricing yet.

I did check McMaster, but their pricing is high.

I should have been clearer in my original post - this is for the mixing elbow and, so, must be metal.

I am still in doubt as to wall thickness. Sched 10 is 0.12" whereas 14ga is 0.075" and 16ga is 0.625" and one of these might be quite adequate (and more economic. Tube will be nominally 3" OD to match the 3"exhaust hose.

Comments?

 

[Bmarler]

Thanks for this - Alaskan was a good tip - they have an impressive selection of options other than the standard sched 10 pipe size. I have not seen pricing yet.

I did check McMaster, but their pricing is high.

I should have been clearer in my original post - this is for the mixing elbow and, so, must be metal.

I am still in doubt as to wall thickness. Sched 10 is 0.12" whereas 14ga is 0.075" and 16ga is 0.625" and one of these might be quite adequate (and more economic. Tube will be nominally 3" OD to match the 3"exhaust hose.

Comments?

I’d have a better feel for thickness if I knew the design of the system. But personally, I wouldn’t drop below .120 wall, especially for the inside tube. For anything that’s uncooled and covered in lagging, I’d go .250 wall.

 

[SteveK]

Have you asked Metal supermarket in Langley

 

[Nick F]

Have you asked Metal supermarket in Langley

I spoke with them at the Burnaby location and they had nothing, but I will now try the Langley location. I use them often.

 

[Tired Trawler]

Have you considered a cast stainless steel mixing elbow from HDI Marine?
My experience with light gauge stainless elbows has not been good, very expensive and unacceptable lifespan due to fatigue / stress cracking.

 

[Nick F]

Have you considered a cast stainless steel mixing elbow from HDI Marine?
My experience with light gauge stainless elbows has not been good, very expensive and unacceptable lifespan due to fatigue / stress cracking.

Unfortunately, not an option due to geometrical constraints. It pretty much has to be a custom setup.

 

[mvweebles]

Have you tried the automotive racing supply places? Summit Racing being one - they carry 304 with a couple different wall thicknesses.

https://www.summitracing.com/search/part-type/exhaust-tubing

Peter

 

[Nick F]

Have you tried the automotive racing supply places? Summit Racing being one - they carry 304 with a couple different wall thicknesses.

https://www.summitracing.com/search/part-type/exhaust-tubing

Peter

I prefer 316 (316L)

 

[luna]

Although they are becoming increasingly rare, the smaller scrap metal dealers may prove to be a source for this kind of thing. The large ones on Mitchell Island don't really cater to individual sales, they seem to sell only truck load quantities, but there remain a couple of small family run shops locally.

I've have found treasures cheap at both Capital Salvage on Triumph St. and North Star Metal on Franklin St. Both have websites, but you really have to go and look as they generally don't keep an inventory list. Happy hunting.

 

[maddox]

https://www.onlinemetals.com/
I’ve purchased from them several times

 

[grumpyfnq]

Mixer Elbow

I know 316 is a pretty standard go-to for these but I have fabricated and bought ready made several with mixed results. Some showing pitting at 12 mths some like new after several years.

Heavy duty commercial guy I have worked with for years just laughed and said 'wrong stuff'. Commercial boats here mostly use 2205, a high chrome stainless as it is nickel hot exhaust eats. Common in oil industry but a bit harder to find than 316. No harder to work with.

But I have had cast iron Volvo elbows last many years despite corroded appearance.

For sealing inlet elbow into mixer any good quality liquid pipe sealer will do as that joint only sees discharge water temperature, hopefully only warm.

Exhaust mixer elbows, the story that never seems to end, only pause for a while.

 

[Bensjoy]

Manifolds

Marine Manifolds on Long Island, New York can fabricate replacement manifolds, risers etc. in stainless steel. It may be worth contacting them at 631-694-0714

 

[Northern Spy]

I too would seek out 2205.

The sad thing is that too the lower mainland of BC had lots of quality fabrication shops and exotic metal dealers with duplex stainless and 6% moly on the shelf. With the downtown in pulp and paper, it's all gone.

I looked through my old contacts and couldn't find any still existing.

 

[Nick F]

I too would seek out 2205.

The sad thing is that too the lower mainland of BC had lots of quality fabrication shops and exotic metal dealers with duplex stainless and 6% moly on the shelf. With the downtown in pulp and paper, it's all gone.

I looked through my old contacts and couldn't find any still existing.

Thanks for the suggestions. 2205 is "Duplex" stainless steel and it (and its superior mate "Super Duplex") are commonly used for subsea equipment in the offshore oilfields where I used to work.

Trouble is that it is super expensive! (It is also stronger than 304 and 316, but I don't need the extra strength.)

Stepping back to look at the big picture, the choices are (in rising order of cost): carbon steel, 304SS, 316SS, Duplex, Superduplex, Inconel, Monel, Unobtanium, etc, etc

I am retired and this whole project is on a budget. For me, thicker wall carbon steel is definitely an option and would certsainly last out my boating career (I am going on 77), but I would feel better using a common stainless (304 or 316).

I am in touch with HDI Marine (thanks, Tired Trawler for the tip) and they have some interesting options. They are apparently planning to produce a mixing elcow for the John Deere starting next year, but I don't know if it will fit my boat. Another option is to purchase just the straight mixer from HDI and weld it to an elbow and my old flange. Trouble is that they do not make a model that has 3"inlet and 3"outlet (as presently in my boat). So I would have to go 3"inlet, 4"outlet, 4x3 reducer which would make for a lot more connections and a "less clean" solution.

 

[Northern Spy]

For a while I was buying 2205 cheaper than 316. 2507 was about the same price. Mainly because of nickel price due to the relatively low nickel content of the duplexes. Moly prices are high now so that is probably the driver in pricing.

Inconel 625 or Hastelloy might be an option. I would use Hastelloy C-22, but definitely not C-276 at the operating temperature of an wet exhaust manifold.

Anyways, call around to heat exchanger shops, as I've bought old stock pipe and tube at bargain prices just to get it out of their inventory. Price isn't necessarily set by quality or composition, but by supply/demand.

 

[twistedtree]

For a while I was buying 2205 cheaper than 316. 2507 was about the same price. Mainly because of nickel price due to the relatively low nickel content of the duplexes. Moly prices are high now so that is probably the driver in pricing.

Inconel 625 or Hastelloy might be an option. I would use Hastelloy C-22, but definitely not C-276 at the operating temperature of an wet exhaust manifold.

Anyways, call around to heat exchanger shops, as I've bought old stock pipe and tube at bargain prices just to get it out of their inventory. Price isn't necessarily set by quality or composition, but by supply/demand.

Pardon my ignorance, but where does 316L fit into this array of alloys?

 

[Nick F]

Pardon my ignorance, but where does 316L fit into this array of alloys?

carbon steel, 304 SS, 316 SS, 316L SS, Duplex, Superduplex, Inconel, Monel, Unobtanium, etc, etc

The "L" denotes low carbon. It is a subset of 316 stainless that has less carbon. In layman's terms, regular 316 has problems of rusting and embrittlement in the weld areas after welding and the L version protects against this.

 

[RedRascal]

If you drive south of the border 90 minutes to Everett Steel they could probably help. https://everettsteel.com/stainless-steel-pipe-c-23_231.html They may have stuff that is not list on the web so it could be worth a call.

They mainly supply materials for large commercial projects but they will cut a small quantity for DIY guys.

 

[Nick F]

Thanks RedRascal - I will give them a call.

 

[RedRascal]

I am curious what you find out and if they will order in a small quantity if they don't have it. Whenever I go there they deal with semi loads of steel so I am not sure how much effort they will put into a small order of something not stocked.

 

[psneeld]

A friend suggested this in an email to me......

"....visit Crescent Yachts on Mitchell Island. They just finished a large yacht and probably have some drops that might suit his needs."