The Yard Guys

[smackdaddy]

Originally Posted by minaret

Since a rudder discussion began this, here's some pics of last weeks Pacific Seacraft rudder after grinding off all coatings. Typical owner repairs, the list of problems was long, including severe saturation. Sent in for factory rebuild, it's the cheapest option for the client. I see rudders like this and worse all the time.

Did you get any word on whether the internal structure or the stock of this was rudder was trashed due to the saturation?

I'm interested in what the failure mode would be on a rudder like this.

[neilpride]

Could be a coincedence, , this morning im called to see some problems in a Beneteau, for the incredulous about Plexus, check it out

First 3 pictures show the preparation for cutting the grid liner in the starboard aft cabin, the surveyor found cracks in the bottom in this área , after ground the gelcoat we see the cracks run deep in the laminate, im not allowed to take pictures from the outside, dirty job...


The next 3 pictures show a fillet of plexus unbonded from the 2 main bulkhead , the one dividing the salón from the cabins, owner reported in a starboard tack sailing to weather , 3 cabinets doors get open and dont close anymore , so i run straight with my flashlight in the cave and found this, i grab the tip of a flat screwdiver and dig it in the crack., the repair call for real fiberglass in the sides of the bulkhead...

[Island Time O25]

Originally Posted by carstenb

Martinsitic SS has magnetic qualites (meaning you can pick up such a bolt with a magnet) - that does not mean it will rust.

I've been told otherwise by several respected sources. That is the less magnetism ss exhibits the better ss it is. But yes I'm aware that several types of ss may be perfectly fine and still have residual magnetism but not supposed to be so strong as to be picked up by a magnet.

[Island Time O25]

Originally Posted by HappyMdRSailor

Instead of using a magnet for provenance... Why don't you use a good source??? Your chances for success are slightly better...

McMaster Carr
Fastenal
Bolt Depot

Yeah, sure but I'd rather be sailing than working overtime to afford "using a good source".

[neilpride]

This is some nices backing plates we do with CF cut outs , just for fun..

[carstenb]

Originally Posted by Island Time O25

I've been told otherwise by several respected sources. That is the less magnetism ss exhibits the better ss it is. But yes I'm aware that several types of ss may be perfectly fine and still have residual magnetism but not supposed to be so strong as to be picked up by a magnet.

source: Mark's Handbook of Standard Engineering

[robert sailor]

When we were in the south Pacific a Beneteau came in with similar problems, furniture had come loose, the owner was very upset. We as cruisers talked about it but at the time none of us were aware that the furniture was not tabbed so we all figured it was poor workmanship.
I don't know this as a fact(getting old) but it seemed to me that they were bonding the bulkheads to the interior liners so if a liner ever let go the structure was heavily compromised. You guys that are dealing with this all the time might chime in and set me straight.

[Terra Nova]

Hylas 70 freezer hatch. First photo shows huge air gaps around shrunken foam insulation. Symptoms were condensation on exterior surface; long run time.

[robert sailor]

Terra Nova,
Nice work! What would cause the sprayed in foam to shrink like that? I'm in the building business and have never seen that. R

[Island Time O25]

Originally Posted by carstenb

source: Mark's Handbook of Standard Engineering

Thanks. I'll read up on that. Will have something to discuss with my marine pros buddies.

PS But knowing the chinese "workmanship" issues I still say that chinese made ss is not what you're talking about.

[Cheechako]

Originally Posted by Island Time O25

I've been told otherwise by several respected sources. That is the less magnetism ss exhibits the better ss it is. But yes I'm aware that several types of ss may be perfectly fine and still have residual magnetism but not supposed to be so strong as to be picked up by a magnet.

That may be true for Austenitic SS (300 series) but 400 series etc is always magnetic. (it's about 85% iron!) It is high strength compared with 300 series if it's heat treated. It may not be as corrosion resistant, not entirely sure... I think it's rare to see it in marine applications... better used for cutlery!

[Island Time O25]

Originally Posted by Cheechako

That may be true for Austenitic SS (300 series) but 400 series etc is always magnetic. (it's about 85% iron!) It is high strength compared with 300 series if it's heat treated. It may not be as corrosion resistant, not entirely sure... I think it's rare to see it in marine applications... better used for cutlery!

I recall that this may have been my buddy's explanation for looking for nonmagnetic ss in marine apps. Also I read that stronger ss is more prone to rust and is more brittle. While less prone to rust ss is more elastic. Certianly if I had the budget I'd go with titanium all the way but that's not happening unless I win the lottery. And I don't even buy the tickets.

Speaking of 300s and 400s series. And this ties in nicely with metric vs imperial thread. The rest of the world uses A4 and A6 if I'm not mistaken but we still use 300 and 400 nomenclature. What gives?

[Terra Nova]

Originally Posted by robert sailor

Terra Nova,
Nice work! What would cause the sprayed in foam to shrink like that?...

Thanks. I can't be certain, but the foam must have reacted to some non-compatible solvent out-gassing from the resin.

[UNCIVILIZED]

Guys, whether you're looking for the properties of a specific stainless alloy, or those of any other material, go to www.MatWeb.com
In addition to a material's physical properties being listed, there's often enough an abridged writeup on the material.

Also, the site provides, a list of producers & or retailers (if available). - KEY RESOURCE
So that likely with a few calls, & proper "coaxing" you can/could find out what you want to know it terms of the pros & cons of a specific material. Especially if you wind up talking to a retailer for the stuff, who's under the impression that you are shopping for X, & are more than just a small buyer. And said persona at the company will be looking to steer you to the most suitable material for the application in question, which they make (plus that's the most profitable for them to sell).

[1affiah]

RE:Stainless Steel Bolts Bleeding Rust

If you use steel tools on your "Gold Standard" stainless steel bolts (ie: clean off the old sealant with a wire wheel) they will also bleed rust from the imbedded micro particles of steel.