Questions

Thums Up · Post by **Thums Up** » May 30th, '11, 15:02

I have a few questions for my rebuild.

Is 316 stainless on the rub rail that much better for the cost than 304? Price difference is over a grand to do the boat. 30' Ray Hunt Chris Craft which uses just a 1" half round no plastic backer.

Anyone know of a good place to get HD tuna door hinges in Stainless?

Thanks! Greg

Peter · Post by **Peter** » May 31st, '11, 06:16

You definately want 316, not the 304.

An interesting aside:

When staniless steel was first marketed it was dubbed "stainless" because it stains less.... if it did't rust at all they would have called it "StainFree" steel. (from handbook on Selecting Carpenter Stainless Steels)

There are lots of formulations and grades used for various purposes. Most are not magnetic at all. Some are magnetic to a certain extent, but at the expense of rusting a little more easily. Common kitchen knives are often 304 which is good enough in fresh water diswashers if they are dried off. And they also stick to those magnetic knife holder strips... But if you ever get ahold of a realy goood chef's knife like a Sabatier au carbon (not a standarad Sabatier) it is from carbon steel which takes an edge like a razor with a few licks on the steel, but turns black in less than a minute when exposed to any sort of corrosive agent such as cutting open an orange... and never ever goes through the dishwasher... The difference in the way the two stick to a magnetic holder is remarkable.

In highly corosive environments like salt water you need 316. I believe the 316 contains more chrome and is harder to machine and harder to weld than the 304.

There are even more exotic formulations than 316 for super serious corrosion resistance, but the costs become prohibitive for most pieces.

When you get your new 316 stainless it will likely have small bits of ferrous metal imbedded in the surface so the first week outdoors it might show spots of rust here and there. Don't sweat it, just polish them out. Most of them won't return for a very long time after that.

Peter

Harry Babb · Post by **Harry Babb** » May 31st, '11, 07:50

Greg, Peter is right on target.......316 is the best choice and 316L is even better.

316 typically contains .08% carbon. 316L, the "L" is for Low Carbon, typically contains .03% carbon.

Strangely enough 316 Stainless Steel is made up of about 67% Iron with the addition of Chrome and Nickel to make it "Stainless"

If you intend to weld your rail together.....be very careful. Heat without subsequent treatment will destroy the materials corrosion resistance in the "Heat Effected" zone.

For the best corrosion resistance, if welded, it is imperative that you have an excellent fitup, then TIG weld a very small weld bead applied very quickly and cooled rapidly.

Failure to cool it rapidly will cause Carbide Percipitation in the "Heat Effected" zone and that is where the rust and corrosion will come from.

Don't know if you were going to weld or not but thought I would share what I know about welding SS.

hb

Thums Up · Post by **Thums Up** » May 31st, '11, 18:05

Great Info., thanks guys!

In Memory Walter K · Post by **In Memory Walter K** » May 31st, '11, 18:12

Single best reason not to buy your "stainless" screws from a hardware store. That one rusting screw and it's inherent stain can make you nuts!

Tony Meola · Post by **Tony Meola** » May 31st, '11, 21:39

Greg

Sounds like you are cooking on the project. I have been tied up, but I will swing by one Saturday morning to catch up and see how it is going.

Thums Up · Post by **Thums Up** » Jun 1st, '11, 17:10

Hey Tony,

Not cooking like I want.....Slow as heck to be honest. But, feel free to stop on by. Be great to see you and get your opinions on stuff. Not there every Sat.. But most!

Raybo Marine NY · Post by **Raybo Marine NY** » Jun 1st, '11, 17:58

are you sure that price difference is not hollow back versus solid?

AndreF · Post by **AndreF** » Jun 1st, '11, 19:08

Only use SS wire brush to clean it up, welders always told me.

randall · Post by **randall** » Jun 1st, '11, 19:36

AndreF wrote:Only use SS wire brush to clean it up, welders always told me.

very good advice.

Thums Up · Post by **Thums Up** » Jun 2nd, '11, 05:44

Thanks.... all good stuff. Raybo I wish that was it. 1" solid back is about 500-750 depending on the supplier per 20' (316).

Also, I am not going to weld. Just butt joints.

Any leads on tuna door hinges....

mike ohlstein · Post by **mike ohlstein** » Jun 2nd, '11, 10:26

http://www.bosunsupplies.com/products2. ... duct=L5961

Thums Up · Post by **Thums Up** » Jun 3rd, '11, 19:34

Thanks Mike. Pricey but they will do the job!

mike ohlstein · Post by **mike ohlstein** » Jun 4th, '11, 07:33

I think that they have less expensive ones, as well.

http://www.bosunsupplies.com/Deck_hinges.CFM

bertram31.com

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