Large diameter thru hull fitting removal

[RMI LLC]

I’m sure someone out there has run into this before.  Got a boat on the blocks with worn out seacocks, which usually isn’t a big deal, but the 4″ thru hulls are of a different design than we usually see.  Instead of the “ears” that usually are found protruding into the ID of the fitting, these have slots in the ID to receive a male profile tool.  I haven’t been able to find a matching set or a tool designed for these fittings, so we fabricated one.

Usually with a little heat, we can back a through hull out with no issue.  That said, 4″ is big… lots of thread, lots of surface area, lots of friction, and lots of space for corrosion.  These things haven’t budged.  

Before we get “surgical” and start cutting them out, I wanted to see if anyone else had a trick up their sleeve.  It would be nice to find the proper tool for these, though so far the one we made seems to have plenty of bite.  If I cut them out, we’ll have to custom machine the new ones to make the flange diameter fit the profile of the boat, so just looking for options before we go that route.

Topic

[Tony Athens]

Adding to Clark’s post———– 85-5-5-5,  AKA 85- triple nickel  bronze is considered the standard of the industry as to a best compromise for most under water marine thru hulls, valves, etc..

It’s part of what is  called   a group of copper based alloys  gun metal alloys. Also called red brass in some cases. 

The problem is you to have to trust your supplier these days as absolutely  in many cases, IMO  85-5-5-5  from 30+++  years go was better than it is today..   But also in that group of gun metal alloys,  some have more copper, more tin and less zinc..

We tend to trust Groco, Perko, Buck Algonquin ( although they seem to supply some Italian made valves that may not meet that spec–maybe DZR brass?)  and  a few other suppliers ( actually no choice) these days as they own the market. We also trust our SMX suppliers for the parts we have made out of 85-5-5-5.. 

Long story shout– 85-5-5-5 is a good choice for the valves you need.. If I were you, I’d tend to go GROCO.. 

 

 

[Clark Leighs]

I expect you are aware of a brass called 85-5-5-5 which is suitable for seawater use.

85% copper, 5% zinc, 5% lead, 5% tin.       THe zinc % is small enough to not be a problem for life in seawater.

Lead and tin and of course copper are highly resistant  so the result is a highly resistant metal.

I will leave you to find sources of the pipe  but one I ran across is following:

 

Red Brass Pipe – Trenton Pipe Nipple Company, LLC

 

 

They apparently stock up to 6″ pipe.     You will need  to confirm that and ask them specifically  about the suitability of thier 85-5-5-5 for seawater use.

I hope this does not just cloud your issue

THe only other thing I can suggest is both Groco Marine and  Buck Algonquin  MYA be able to help with advice and suggestions.

[RMI LLC]

Thanks, Tony.  The goal was to not have to destroy the fittings to get them out (with the supply issues we’ve had lately, I’ve learned not to get destructive unless I have a replacement part on hand already.

The next challenge on these big systems is the new valves are exactly 1″ shorter than the old valve.  The old valves are not repairable, and the existing piping coming off the valve will not clear the engine bed/stringer without some additional height.  Any good sources for 4″ diameter marine grade brass pipe?  For pieces this short, I’ll likely end up having to thread them in the lathe.

 

-Dan

[Tony Athens]

Is “Tenacious” the right word here?

Good job!

[RMI LLC]

got them out this morning.  Ended up having to heat and cool them several times, then holding upward pressure on the tool with a hydraulic cylinder while I turned it with a breaker bar.  Slow and difficult to turn out, even with a cheater pipe.

I’ll post some pictures when I get a chance.

[Tony Athens]

Good pictures of all might bring a response

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