Tobin bronze/Naval Brass tubing source

[redbopeep]

I have a pinked-out stern tube--prop tube, whatever you want to call it tube...as an aside, it has an (inside) cutlass bearing cast with the name Hyde on it. The inside bearing has a hole/grease fitting, the outside one, no grease fitting. The tube needs to be replaced. I can find new Naval Brass tubes with rubber inside--but they're all the wrong proportions and not long enough to go through all our deadwood/sternpost etc.

Anyone know who carries a thin-walled Tobin Bronze/Naval Brass/Admiralty Brass tubing? What was there is ID=2.0", OD=2 3/8"; the length needed is approximately 32." Both ends are pipe threaded for the inside and outside cutlass bearings. We can do that here, of course, but just looking for the metal.

Thanks!

[Tim Whitten]

In the past, I have gotten naval brass rod and some bronze tubing from McMaster-Carr.

http://www.mcmaster.com/

[redbopeep]

Tim, thanks. Yes that is a good source for stock and some tubing, also I've gotten bronze from MSC before and from Alaskan Copper. The big issue here is finding the long length of Naval Brass/Tobin Bronze. The tubing seems to be used in marine applications but already cut up in little pieces. Even the bronzes offered by your source only come in 13" lengths. I need 32" length. Always something....

[FSS172]

Try these folks:

http://www.nationalbronze.com

[David Conard]

Have you tried Atlas Metals in Denver?
http://www.atlasmetal.com/

[Canoez]

Tim, thanks. Yes that is a good source for stock and some tubing, also I've gotten bronze from MSC before and from Alaskan Copper. The big issue here is finding the long length of Naval Brass/Tobin Bronze. The tubing seems to be used in marine applications but already cut up in little pieces. Even the bronzes offered by your source only come in 13" lengths. I need 32" length. Always something....

Most of the stock from McMaster-Carr is available by the foot, or multiples of a foot. You should be able to buy a 36" length with no problem. Might not be the right diameter, tho...

[Concordia...41]

I second David's Atlas Metals recommendation.

SARAH is sporting a fair amount of their bronze rod (keel bolts) and bronze flat stock (cut into strips for frame reinforcement). IIRC they had to cut their stock down :eek: to 5' lengths to ship UPS.

Fine folks and generally present at the WBS. :D

[JakeScott]

have you considered copper nickel? Tubing and pipe should be readily availible and probably fine for a new stern tube.

Jake

[Jay Greer]

I deal with Atlas. They always are able to fill my needs.
Jay

[redbopeep]

Followup--

Thanks all, I've sent an email rfq to National Bronze and will call Atlas today. Hopefully one of the two will have the material needed.

I didn't realize that McMaster had longer lengths than those posted in their catalog--MSC certainly only has what's in their huge catalog so expected both companies to be the same as they are similar on so many things.

Typically we've found Alaskan Copper to be able to beat Atlas on price for bronze rod stock but not necessarily on plate. Lots of keelbolts with silicon bronze from Alaskan Copper co because of that. We did get Tobin bronze for some of the chainplates from them as well. I've got a quote from Alaskan on the silicon bronze for the rudder stock and another quote on the bronze for the rudder tube (they quoted bearing bronze for that tube...said they couldn't get Tobin bronze....). They're high in price on both and though (always check against onlinemetals.com which is a little high) I requested a quote two weeks ago on this prop tube (is that this thing called "shaft log"?) part and they haven't gotten back with me on it. I expected them not to quote tobin bronze/naval brass but instead bearing bronze which is why I posted here asking for sources for Tobin.

I'll keep my fingers crossed about Atlas and National....

Thanks! again, all.

[redbopeep]

Atlas doesn't have it--oh, wait,they did say they can provide 3" ID....how this would help....I don't know.......no, no, no, we want the shaft log to be INSIDE the deadwood not busting out of it...

Haven't heard back from others yet.

[redbopeep]

Update and HELP please!!!!

I've talked with Atlas, National Bronze, Alaskan Copper, RV Wagner, Anchor Bronze, Farmer's Copper and a few others...:( no materials that fit the bill.

Nobody, that is NOBODY has what I need. One of three things end up wrong...At least I now have what I need distilled down into a narrow matrix:

1. Inside and outside diameter must be correct: that’s 2″ schedule 40 pipe with ID of a sliver over 2″ and OD of 2.375″.

2. Corrosion resistance to seawater must be there and there are a range of alloys that fit this need.


3. Final thing, since the shaft log literally sits right up against some 4 ft long silicon bronze bolts which hold the back end of the boat together...the material chosen must be “less noble” than silicon bronze so that in the presence of seawater and stray current, the shaft log will not cause degradation of the silicon bronze keelbolts.



This combo of requirements is making it darn near impossible to find something for the shaft log. I’ve found copper-nickel shcedule 40 pipe at Farmers, but it is more noble than silicon bronze (I've recently read a report on the degradation of silicon bronze fasteners in the presence of copper-nickel hull sheathing :eek:), I've found the right materials on the wrong diameters or plain brass or red brass with limited corrosion resistance in seawater...argh....

[redbopeep]

If it is just a shaft log, and you can't find pipe nor tube in the correct dimensions, then buy or make one from fiberglass, or schedule 80 PVC.

Backfill the sucker with epoxy and forget it.

Lets see if I can match the tone of your reply :rolleyes:

When we've gone to all the bother of finding the right materials for so many other of our projects, it seems a waste to half-arse this particular project.

Schedule 80 pipe (which is available in silicon bronze, by the way) doesn't give desired clearance on the prop shaft. That's the easy solution if adequate clearance were provided.

Its a long enough shaft log for alignment to come up. If I didn't care about alignment between outside/inside cutlass bearings nor about leaking around the prop shaft due to alignment issues nor about wear on the prop shaft...this would be easier and a fiberglass tube, etc, could be employed. But I do care.

The inside cutlass bearing had a grease fitting with associated packing for stuffing box. I'd think alignment issues will certainly cause problems with the stuffing box and wear on the prop shaft.

This is a 29 ton boat that I don't relish hauling out to deal with a screw up because we've done something not-quite-right. Therefore, since what was there in the past worked great, didn't leak, etc, we'd like to replace in kind. We're only talking about $200 bucks worth of material if I can just find it.

If it were a little boat or a project with lesser consequences to a screw up, sure, I (might) be more willing to do something different than what was there.

Thanks for your reply. :)


P.S. Bankdorys, I'm so honored that 25% of all the responses you've posted as Bankdorys on the woodenboat forums have been to my posts.
;)

[Gary E]

I used to make tons of stuff for the US Navy...
This co had no problem delivering materials
http://www.hillmanbrass.com/

[kc8pql]

That's kind'a the way I read it too. Fiberglass will do exactly what you want. Don't discount it out of hand.

[redbopeep]

That's kind'a the way I read it too. Fiberglass will do exactly what you want. Don't discount it out of hand.

The question/issue for us about fiberglass related to the fact that the inside and outside cutlass bearings are both threaded onto this bronze tube--it seems that this threading does the job of holding alignment. A filled resin product can be nicely threaded, true, but not sure where we'd get the appropriate fiberglass filled resin tube either. With no real knowledge what-so-ever of fiberglass tubes...my focus remains on finding an appropriate alloy tube/pipe.

I really do believe that there's a supplier out there with what we need--I just haven't found it and am running short on time to get this taken care of.

Thanks for your response. If you could comment regarding threading fiberglass tubing, I would appreciate it as that's the "discount" factor on fiberglass.

[kc8pql]

Your setup sounds a bit out of the ordinary. Do you have some sort of variable pitch prop? Usually the stuffing box and stern bearing have a pilot (unthreaded) that fits into the tube, but the fitting itself bolts to the deadwood.

[redbopeep]

Tone??? I read this post as someone who has established that they CAN'T find the material at three very reputable suppliers and has voiced it in a desperate manner. My reply was in earnest response to this.


I will be careful to avoid replying to any of your posts as it seems to worry you.

Hey, Bankdorys, when someone like me puts themselves out there, honestly stating their concern, worry, lack of knowledge, or thought process, its really nice to get responses from the WBF community trying to address the actual concern or issue.

I've made a couple posts where I just laid out my thought process, indicated my level of worry/concern, and asked for input; I also respond to posts other people make when I have something to offer to them. From your responses to my various posts, I imagine that my posts have been pushing your buttons, since you don't seem to respond to many other people's posts (unless you also delete those responses as you deleted the ones you made to my posts). I guess a direct plea for help can push some people's buttons. Sorry for that.

Many times, this is one of the only places for wooden boat owners to get info from people who have had the same experience and will share it. I greatly appreciate this. Its alot better than having the new boat owners around saying--epoxy, epoxy, 5200, 5200, goop, gloop...why do you have that wooden boat, anyway...

I continue to appreciate posts educating me and others on the + /- of using different materials and methods than I may be familiar with or may have the wrong idea about. I am especially appreciative of the WBF members whose posts manage to portray their sincere desire to help. I admit, if I think the tone of a reply can be easily read to be belittle the concern of the original poster, or is sarcastic, or is posted simply as a play on words of another post, then I'm not pleased to be on the receiving end of such a reply which does me little good. I'd much rather have the good folks of the WBF refrain from posts of the "just deal with it, lady" nature and instead keep up the helpful posts that I keep coming here to read.

[redbopeep]

I used to make tons of stuff for the US Navy...
This co had no problem delivering materials
http://www.hillmanbrass.com/

Just emailed them, keeping my fingers crossed :)

[redbopeep]

Your setup sounds a bit out of the ordinary. Do you have some sort of variable pitch prop? Usually the stuffing box and stern bearing have a pilot (unthreaded) that fits into the tube, but the fitting itself bolts to the deadwood.

The brand is Hyde. Old but in good shape. Expect it may have been installed in 1939 timeframe with a repower of the boat. As far as we know, there was never a variable pitch prop. We considered putting one in, but don't have enough room in the deadwood for the even larger diameter shaft log it would take (4" or more). The stuffing box and stern bearing both have 4 holes for lag bolts to go into the deadwood but it is clear that they are superficial and may only serve to keep vibration from unscrewing them from the shaft log.

[FSS172]

If you don't have any luck with Hillman, how about one of these options: 1) getting the closest tube you can in the right material and having it machined to your specs, 2) machine your existing stuffing box and stern bearing to fit the new tube or if necessary buy new stuffing box/stern bearing and have them machined to fit it that's cheaper. I understand the OD needs to fit the existing shaftway, but if the ID or getting the threads to match is the issue, one of these possibilities might work for you. Or one more idea FWIW - lose the threads and use just a machined fit (with or without sealant) between the components. The stern bearing and stuffing box fasteners serve to press those fittings into the stern tube and retain them. It's worked on my boat...

[Pierce Nichols]

1. Inside and outside diameter must be correct: that’s 2″ schedule 40 pipe with ID of a sliver over 2″ and OD of 2.375″.


If you can get a piece of acceptable material that's close to those dimensions, you should be able to get any decent machine shop to turn down the outside and bore out the inside for a non-horrendous price. If you go that route, the appropriate raw material may be sold as 'hollow bar' rather than pipe or tube.

OTOH, given the amount of trouble you've had, if I were in your shoes, I would seriously consider alternative materials, such as fiberglass. You could even have threaded ends made by a local machine shop and epoxy them into the tube.

[redbopeep]

If you don't have any luck with Hillman, how about one of these options: 1) getting the closest tube you can in the right material and having it machined to your specs, 2) machine your existing stuffing box and stern bearing to fit the new tube or if necessary buy new stuffing box/stern bearing and have them machined to fit it that's cheaper. I understand the OD needs to fit the existing shaftway, but if the ID or getting the threads to match is the issue, one of these possibilities might work for you. Or one more idea FWIW - lose the threads and use just a machined fit (with or without sealant) between the components. The stern bearing and stuffing box fasteners serve to press those fittings into the stern tube and retain them. It's worked on my boat...

The schedule 80 silicon bronze should be the same as as schedule 40 on OD with no problem. I'm not a machinist but I don't know about inside milling something 32" long to a larger ID (schedule 40 is 2.06, sch 80 is 1.939).

Cutting the threads is no big deal if the material can be found, but I hear you regarding a machined fit which would be more normal.

Thanks.

[kc8pql]

What is the diameter of your shaft? Typical for a 2" tube would be about 1 1/2". If that's the case, 1.939 should provide enough clearance. You don't need to bore out the whole tube. Just mill the ends to accept your threaded fittings.

[redbopeep]

What is the diameter of your shaft? Typical for a 2" tube would be about 1 1/2". If that's the case, 1.939 should provide enough clearance. You don't need to bore out the whole tube. Just mill the ends to accept your threaded fittings.

No, that would be great but it's a 1.75" prop shaft.

The folks at Hillman don't have what I need and state that Farmers is the best bet. I think Farmers was the place with schedule 80 bronze.

I've noted that Johnson/Duramax has the correct diameter/wall thickness Naval Bronze in use on one of their cutlass bearings (13" or 7" length though) and I'm in the process of tracking down an email for them since I've heard that they also do custom work. I might be able to simply get them to do a shaft log of the length I need (32"). The particular cutlass bearing that they sell is intended for water lubrication and has a neoprene lining pressed into it. I'm really just wanting the shell w/o the lining which, because it fits tight to the prop shaft seems like it makes the entire tube a "wear item".

Will let you know what I learn. Thanks for your post.

[BrianM]

If you can locate a machine shop with the right gundrilling machinery, you can have the ID of a Pipe or Tube or Solid Bar Stock machined to your specifications.

GunDrills don't wander like a drill, thus the name.

http://www.technidrillsystems.com/images/gundrill_s.jpg

Since San Diego is a Navy town, there MUST be someone who can do the proper boring near the shipyard. Mr. Fleming might be knowledgble on that source?

[redbopeep]

If you can locate a machine shop with the right gundrilling machinery, you can have the ID of a Pipe or Tube or Solid Bar Stock machined to your specifications.

GunDrills don't wander like a drill, thus the name.

http://www.technidrillsystems.com/images/gundrill_s.jpg

Since San Diego is a Navy town, there MUST be someone who can do the proper boring near the shipyard. Mr. Fleming might be knowledgble on that source?


Hi, Brian,

I've asked Dave at Dynamic Marine Machining to give me a bid on doing the deed. Haven't heard back from them but expect that he'll be able to do it reasonably and quickly.

I will compare with getting North Star to bore and thread schedule 80 pipe material that I bring to them. They do mostly big, big things for the Navy and marine industries but can work in a little job here and there quickly. Recently North Star has been less than responsive, else I would have just gone to them directly and not bothered looking for materials at all. They've moved in the last 6 months and had some changes in personnel. They also have temporarily "lost" my old needing-to-be-replaced 10' x 2.5" bronze rudder stock (it was in their shop pre-move) that they're supposed to be working up the estimate on fabricating a new one...and they're not being responsive about finding it to measure off...nor bidding off the drawings of the stock. Ok, that's taking this thread off in a weird direction! Hopefully they'll find it and/or bid it this upcoming week.

I'd love to know from Mr. Flemming or anyone else of other machine shops in San Diego that could do the job if Dynamic cannot.

[BrianM]

Another thing occured to me.. do you really need 1.75" diameter on the props shaft? Bushing down the cutlass bearing housing is not difficult. If moving to a 1.5" shaft allows access to readily available pipe/tube that does the job, I'd rather tackle that then pay for a custom gun-drilled shaft.

How many horsepower do you intend to run?

This shaft diameter calculator suggests that unless you are running 75HP or more, you don't need anything over 1.5"

http://www.cembercidenizcilik.com/modeldxf/dxf/SAFT.WK4

[redbopeep]

Yup, we do need the 1.75" shaft. Cummins B5.9M (115 hp) by the way.

[FSS172]

Cummins B5.9M (115 hp) by the way.

Great engine... do any of the marinized versions have a the so-called 'killer dowel pin' problem?

http://www.piersdiesel.com/TechKDP.htm
http://www.dodgeram.org/tech/dsl/Dowel_Pin/tab.htm

The engine in my truck had it; when I found out about it and opened it up, the pin had worked it's way out about halfway. If your engine is of this generation, you may want to look into it.

[Ken Hutchins]

Either use fiberglass or make a pattern and have a casting made, fiberglass is a heck of lot cheeper. Hundreds of fiberglass suppliers on the WEB.

[redbopeep]

Great engine... do any of the marinized versions have a the so-called 'killer dowel pin' problem?

http://www.piersdiesel.com/TechKDP.htm
http://www.dodgeram.org/tech/dsl/Dowel_Pin/tab.htm

The engine in my truck had it; when I found out about it and opened it up, the pin had worked it's way out about halfway. If your engine is of this generation, you may want to look into it.


dunno....:eek:

[redbopeep]

Well, we finally just purchased Aluminum Bronze Hollow Bar (2" id 2-3/8" od) which is slightly less noble than the silicon bronze but better than the naval brass that was there. $130.50 including shipping for a pre-cut 39" length from Online Metals.

Turns out the threads on both ends of the shaft log are simply NPT, but our pipe threading stuff is in storage back in Maryland. Always something! The cutlass bearing housing actually had an "slide in" extra sleeve screwed onto the 2 3/8" od of the shaft log and it. Its tapered 2.7" front and goes down to 2-5/8" aft where it hits up against a standard (rubber within a bronze tube) cutlass bearing). When the guys were taking the shaft log and cutlass bearing housing apart, this little sleeve fell to bits. The machine shop (Dynamic on Shelter Island) will have to fab up this part. Going over there today with all the "parts" so we'll see.