Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 25-11-2008, 08:27   #1
Marine Service Provider

Join Date: Oct 2007
Boat: Endeavour 42CC
Posts: 1,182
painting mild steel

I'm thinking of making a flopper stopper. simple 2 piece steel with a hinge.
Stainless is expensive so how about mild sheet steel and then paint it?
I would use 316 ss for the hardware.
My question is how to best paint mild sheet steel to protect/delay corrosion in salt water?
__________________

__________________
gettinthere is offline   Reply With Quote
Old 25-11-2008, 09:20   #2
Moderator Emeritus
 
David M's Avatar

Cruisers Forum Supporter

Join Date: Sep 2007
Location: San Francisco Bay
Boat: research vessel
Posts: 10,150
Remove all the loose rust and paint it with multiple layers of an epoxy coating like Interlux 2000 or Interlux 3000. Then try not to chip the epoxy. The only way to stop rust is to seal out the oxygen. Zinc chromate only slows down the inevitable.

You could also have it galvanized. It would not be very expensive to have that done.
__________________

__________________
David

Life begins where land ends.
David M is offline   Reply With Quote
Old 25-11-2008, 10:28   #3
Registered User

Join Date: Oct 2006
Location: The boat lives at Fidalgo Island, PNW
Boat: 36' custom steel
Posts: 992
Use two-part zinc primer epoxy paint.
__________________
John, sailing a custom 36' double-headed steel sloop--a 2001 derivation of a 1976 Ted Brewer design.
Hiracer is offline   Reply With Quote
Old 25-11-2008, 11:58   #4
Moderator
 
cabo_sailor's Avatar

Cruisers Forum Supporter

Join Date: Mar 2008
Location: Tarpon Springs FL
Boat: Cabo Rico 38
Posts: 1,905
We have some local companies that do powder coating. I should imagine that would work. For the DIY, Sears was marketing a small powder coat kit for around $50.
__________________
cabo_sailor is offline   Reply With Quote
Old 25-11-2008, 13:38   #5
Senior Cruiser

Cruisers Forum Supporter

Join Date: Nov 2005
Location: Tasmania
Boat: VandeStadt IOR 40' - Insatiable
Posts: 2,317
Images: 91
Don't do it.
Use. Stainless. Steel.

Two reasons:
Firstly, by the time you buy all the paints and products that you will need for coating up the mild steel it will cost you as much as it would have to use stainless in the first place.
Secondly, if it is a hinge, it will have moving parts. If it has moving parts, you will certainly wear away at your paint coating. Once the paint coating is worn away you will get rust. Once youhave rust you will never get rid of it. The metal on metal contact is going to be in the hinging part and the performance will end up compromised.

Seriously, you will end up regretting not using stainless.
__________________
Weyalan is offline   Reply With Quote
Old 25-11-2008, 14:01   #6
Registered User

Join Date: Oct 2006
Location: The boat lives at Fidalgo Island, PNW
Boat: 36' custom steel
Posts: 992
Quote:
Originally Posted by Weyalan View Post
Don't do it.
If it has moving parts, you will certainly wear away at your paint coating.
Man O Man. I'm not familiar with these things.

If there are moving parts, I concure 110%. Paint will not work.
__________________
John, sailing a custom 36' double-headed steel sloop--a 2001 derivation of a 1976 Ted Brewer design.
Hiracer is offline   Reply With Quote
Old 25-11-2008, 15:24   #7
Registered User
 
captjcook's Avatar

Join Date: Jul 2008
Location: Fort Lauderdale Florida
Boat: Northstar 1500, 35'
Posts: 318
To Gettingthere,
I am a mechanical engineer. I am professionally reconstructing a 34 foot steel Ketch. I have been using POR15 as a primer, it it a bit tricky for timing between coats and top coat...There is no perfect coating for mild steel, and I would second the galvanize. With a hinge involed as previously stated you are asking for trouble. I find that SST or in engineering speak CRES (corrosion resistant steel) that the price per pound is not that formidable. That said I am curious about a "Flopper Stopper" having a hinge in the first place....I might be wrong ( has happened in the past) but flopper stoppers look a bit like mushroom anchors working on volumetric displacement like birds on a shrimp boat/trawler, anyway I work closely with a fabrication shop, having many things built at the lowest cost, I just don't see stainless especially 304 (may weep a bit) being that expensive. If you provide a sketch, I will give you a reasonable estimate to build or to expect from a fabricator. You are not talking rocket science!
__________________
captjcook is offline   Reply With Quote
Old 25-11-2008, 15:48   #8
Registered User
 
Jesse's Avatar

Join Date: Apr 2008
Location: Oro Bay Puget Sound
Boat: Irwin sloop
Posts: 374
I made a pair for a friend using UHDP "ultra high density paper" made by Richlite. It's quite heavy and damn near bullet proof and requires no protective coating at all. he used them for 11 years then sold them with the boat. Woodworking tools are all you need and you can drill and tap it for threads too.
Jesse
__________________
Jesse is offline   Reply With Quote
Old 25-11-2008, 16:07   #9
Marine Service Provider

Join Date: Oct 2007
Boat: Endeavour 42CC
Posts: 1,182
The hinge and hardware will be stainless and bolted to the plate with stainless screws.

I can get a steel plate for about $20 but I've been seeing SS sheet of about 24" X 24" at over $100. Am I seeing bad pricing? This sheet has to be stiff enough to stay flat while flop-stopping. Perhaps 12 gauge?

A bit of rust over a long term isn't a big deal. This isn't anything structural at all.
__________________
gettinthere is offline   Reply With Quote
Old 25-11-2008, 16:39   #10
Registered User
 
captjcook's Avatar

Join Date: Jul 2008
Location: Fort Lauderdale Florida
Boat: Northstar 1500, 35'
Posts: 318
ok now I get the hinge part it can fold up on the down stroke. When I go to my I would like to say friend, He has a drop pile (eccess/scrap) I always can find pieces close to the size I need and then shear to size. You may be dealing with a fab shop that would have to order a full sheet to give you your four square feet, it is not uncommon to charge for a full sheet even if the customer needs less, not wrong in my opinion...if they don't use it all the time, they don't suffer a loss for inventory. Sometimes I have to wait til the shop has leftover in the gauge I need, or go to another shop. Ask for the proper size pieces ie: 12 x 12, shearing is a buck to a buck and a half a stroke, let them know an eighth (Whatever) less is ok if you can do that, they may have a piece close. I would get four 12 x 12 x 1/8 11 gauge pieces for less than $60 easy. 16 gauge (1/16) or 14 ga may be cheaper still. rolled stainless is stiff stuff.
Jim
__________________
captjcook is offline   Reply With Quote
Old 25-11-2008, 17:47   #11
Marine Service Provider

Join Date: Oct 2007
Boat: Endeavour 42CC
Posts: 1,182
Quote:
Originally Posted by Jesse View Post
I made a pair for a friend using UHDP "ultra high density paper" made by Richlite. It's quite heavy and damn near bullet proof and requires no protective coating at all. he used them for 11 years then sold them with the boat. Woodworking tools are all you need and you can drill and tap it for threads too.
Jesse

Jesse

I tried many search variations on your "UHDP paper" but struck out. Can you give more info? Perhaps a spelling error?

Also, I will need to bend the sheets, does this stuff form or bend?
__________________
gettinthere is offline   Reply With Quote
Old 25-11-2008, 19:42   #12
Registered User
 
Jesse's Avatar

Join Date: Apr 2008
Location: Oro Bay Puget Sound
Boat: Irwin sloop
Posts: 374
You should be able to get all the info available by Googling "Richlite". I'm told there are many uses for the stuff, I've seen it used for transoms on boats with outboards or out drives, counter tops, hatches, fuel docks and high traffic areas. It doesn't seem to wear at all and so far nothing I've found disolves or discolors the surface. But I don't think it's gonna bend worth a hoot, I don't know if heat would help but it's doubtful. But it is the strongest and toughest material I've found that can still be worked with woodworking tools.
Jesse
__________________
Jesse is offline   Reply With Quote
Old 26-11-2008, 00:35   #13
Senior Cruiser
 
roverhi's Avatar

Cruisers Forum Supporter

Join Date: Aug 2005
Location: Kona, Hawaii, Carlsbad, CA
Boat: 1969 Pearson 35 #108 & 1976 Sabre 28
Posts: 6,005
Send a message via Yahoo to roverhi
I'll second POR 15. The stuff is super hard and really loves to stick to steel as long as it's grease free. I usually leave stuff to be painted out for a couple of days so it gets an even coat of surface rust before painting. Seems to stick better to light rust than bright metal. But then agian it seems to stick to metal, no matter what.

I have found powder coating to be pretty crappy for stuff that gets abuse in a rust intensive environment. Once you get even the smallest nick in the coating, it begins to rust under the coating until the coating begins coming off in large patches. Doesn't seem to be a cure for the problem as it has happened on every piece of powder coated metal that I own/ed.

Aloha
Peter O.
__________________
roverhi is offline   Reply With Quote
Old 26-11-2008, 01:17   #14
Certifiable Refitter/Senior Wannbe
 
Wotname's Avatar

Cruisers Forum Supporter

Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: Van DeStat Super Dogger 31'
Posts: 7,331
Don't powder coat it. Powder coating IS porous, much more so than a good quality paint system (but harder). Ask any honest (and knowledgable) powder coater !!

Go SST as suggested for worry free long life or just pick any good paint system if you can live with early cosmetic rusting and a shorter life / more maintenance. I am sure the SST will be cost effective over a longer period.
__________________

__________________
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
Wotname is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Painting Hypalon Pura Vida Auxiliary Equipment & Dinghy 50 16-02-2017 04:28
Painting stainless??? AnchorageGuy Construction, Maintenance & Refit 25 18-01-2017 16:03
steinless steel fittings on steel boat Gregoris Construction, Maintenance & Refit 5 14-03-2009 07:03
Painting PVC Gulfislander Construction, Maintenance & Refit 12 18-08-2008 08:27
A question of steel boat painting anglooff Construction, Maintenance & Refit 6 31-07-2007 01:42



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 05:44.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.