Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 14-04-2020, 04:27   #31
Registered User

Join Date: Jul 2009
Location: 2020 - Caribbean, currently Grenada
Boat: Amazon 49 cutter, custom steel boat built in Surrey, Canada
Posts: 731
Images: 1
Re: What is the best way to prime steel?

Quote:
Originally Posted by mvmojo View Post
While not cheap by any means, the Monti Bristle blaster looks awesome!
I bought a second-hand bristle blaster off of e-bay. It really does a great job for preparing surfaces. It's a quality tool and well built.

The downside is that it cannot access tight, confined spaces. You need some room to maneuver the tool around to get the proper angle. The belts are available in two widths, but even the narrow belt can't really get into corners. But for any place that you have good access it is awesome.

Cheers!

Steve
steve77 is offline   Reply With Quote
Old 14-04-2020, 08:49   #32
Registered User
 
Delfin's Avatar

Join Date: Aug 2010
Location: Anacortes, WA
Boat: 55' Romsdal
Posts: 2,096
Re: What is the best way to prime steel?

For small spots, I use a Dremel tool, a la dental work, to grind out a spot of rust. Never had a large bit to deal with except on the aluminum superstructure, and there use 40 grit on an orbital sander. In both cases, asap after grinding I use a zinc chromate anti-corrosion primer from Awlgrip. After that, I fill with 3M vinyl ester filler then sand the area being repaired completely flat. Next step is Awlgrip 545 applied with an air brush. No masking generally, unless there is a clear edge to take advantage of or a color change in the repair area. Next is the top coat, again Awl Grip for me, also applied with an air brush. I generally lay on 3 to 5 coats of both 545 and the Top Coat. Finally, wet sand the area with 1,000 grit to take down the overspray on the edges. Last step is fine cut Maquire's rubbing compound to gloss the area to match the surrounding paint.

After 13 years of usage, many people think she was just painted.
__________________
https://delfin.talkspot.com
I can picture in my head a world without war, a world without hate. And I can picture us attacking that world, because they'd never expect it. - Jack Handey
Delfin is offline   Reply With Quote
Old 17-04-2020, 07:05   #33
Registered User
 
ausnp84's Avatar

Join Date: Mar 2010
Location: UK, Australia, Europe
Boat: Custom Catamaran
Posts: 612
Re: What is the best way to prime steel?

FWIW, I rebuilt a steel schooner from bare hull and used Jotun paints. The yard sandblasted the entire boat and then I applied three coats of epoxy primer, followed by a topcoat of similar. The work was done during a damp summer and there were some times flash rust would appear. I didn’t bother grinding it - just hit it with the three coats and in six years, never had any rust issues.

Be careful with grinders as they flick rust everywhere and wire wheels are lethal... but they’re both great for clearing areas before applying a good epoxy top coat.

Hope that helps!

N
ausnp84 is offline   Reply With Quote
Old 17-04-2020, 07:20   #34
Registered User
 
ejjawhite's Avatar

Join Date: Dec 2014
Location: Hull, MA
Boat: CAL 35 III
Posts: 43
Send a message via Skype™ to ejjawhite
Re: What is the best way to prime steel?

TwoWords: Coal Tar
ejjawhite is offline   Reply With Quote
Old 17-04-2020, 07:29   #35
Registered User

Join Date: Nov 2014
Location: Portsmouth, UK
Boat: Feltz Scorpion II 12m bermudia rig pilothouse
Posts: 47
Re: What is the best way to prime steel?

Quote:
Originally Posted by hpeer View Post
Thanks for referencing the Monti Tool.

They have 4 different machines. I presume you are using the “Bristle Blaster.”?

The “Die Blasted” looks like it may also have application.

Any further comment/advice would be appreciated.

I mostly use a right angle grinder with flap disks but there are times I just can’t get in there.
Yeah totally agree I have found course grit (40 grade) flapper wheels on an angle grinder by far the best thing for small and medium jobs, far far better than grinding discs. However the finish left is not ideal for paint adhesion so I try to finish off with a small hand sand blaster (just for surface texture) if I have access to a compressor. Also I always use a degreaser (MEK if I got it) which will even take away some of the remaining brown coating you get left with if you can only access an area with wire wheels (a last resort).

Dave
davefrediam is offline   Reply With Quote
Old 17-04-2020, 07:33   #36
Registered User

Join Date: Jul 2009
Location: Washington, DC
Boat: Custom Gaff Ketch, Dory hulled, 26' LOD, 33' LOA
Posts: 28
Images: 1
Re: What is the best way to prime steel?

On our Colvin Gazelle we have used a zinc based primer (essentially a cold galvanize) paint called Zinga. Works well and seems to last.

https://www.zingausa.com/
Paul_Carroll is offline   Reply With Quote
Old 17-04-2020, 07:56   #37
Registered User

Join Date: Dec 2014
Location: Amsterdam
Boat: Blokland Steel 10m AftCabin
Posts: 8
Re: What is the best way to prime steel?

Quote:
Originally Posted by chamoy View Post
Hi,
I just bought a 12m steel sloop build in Holland in 1985. No one knew what sort of paint system the boat has. Out on deck it seems like it has a light grey looking thin primer on top of the steel and then a very thick black layer of something very tough that looks like a primer and then paint. Rust is not a big issue, but there are a few places rusting out on deck that I have to tackle.
What is the advice of the experimented steel boat owners out there?
I have heard all sort of ways of doing it, like grinding the steel and 2 part epoxy primer, or sand blasting and 2 part epoxy primer, or just bit of a clean and a rust converter/primer, there is one called Brunox epoxy, that is supposed to by a 1 part epoxy rust converter/primer.
I appreciate any good tips,
Cheers!
Hi there,

I live in The Netherlands and I have a locally made steel motorboat. The usual way treating steel here especially bellow the line is, primer, then, quite often, black Tenco bottom coat (as you described, thick and black) and then a couple of layers of antifouling.
You can treat the small rusted parts with Vactan. First wire brush but leave some rust on.Then apply a good layer of Vactan on it. That converts rust and it is a very good primer too. Then any oil based paint (or black Tenco bottom coat) over it and you are good to go. I just did my over the line repairs and soon I take it out to treat the bottom using the technique I described.

Good luck, those steel sloops are for ever!!!
tasssos8 is offline   Reply With Quote
Old 17-04-2020, 08:23   #38
Registered User

Join Date: Jan 2019
Boat: Beneteau 432, C&C Landfall 42, Roberts Offshore 38
Posts: 1,361
Re: What is the best way to prime steel?

I built a steel ketch back in the late 70's /early 80's.

Protecting the steel was a big issue for me.

No question, # 1 priority is providing a clean surface for the paint to adhere.
This means sand blasting to white metal. An onerous project by any definition.

After blasting, I painted the interior of my boat with a two part coal tar epoxy. This stuff was thick as glue and strong as steel and required 12 gallons to paint the inside of a 38' boat. I'm not sure if this is still available to the general public, but the big ship chandeliers may carry it. It's wonderful stuff. In areas where you can't get too, you can just pour it in...I had some areas, which could not be reached by blasting so I simply just poured the coal tax epoxy in there...and sealed whatever gap there was...
I believe a one part coal tax epoxy is also available, but I have no experience with this product.

The outside of my boat was done with a whole paint scheme. I used a company called Devoe. They can provide you with everything you need. This will start of with a zinc primer, several base coats and then the finish coat. Besides Devoe, there are other paint companies, that can provide the same thing, but I used Devoe and found their product to be very good and easy to apply.

I can tell you, that for as long as I owned that boat, almost 15 years, I never had a single rust problem of note. That boat is still around and still in very good shape, almost 40 years old now.

Once in a while, I would drop something and chip the paint. To patch this area, I would first wipe with a product called Ospho, this will neutralize the rust on the steel, and then I would hit the area with a zinc primer and paint.

When I didn't have Ospho around, I used West System epoxy...marvelous stuff and will cling to anything, including rusty steel. After drying, a quick sand and paint.

The whole objective is to keep moisture, especially salt moisture away from the steel.

99.99% of steel boats will have rust problems on the INSIDE, where water, moisture, etc, will find the smallest unprotected steel component and rust away, often out of sight.

When I sold my boat, the new owners had the hull "sounded" by a surveyor using an ultrasonic device. Nothing out of the ordinary was found anywhere, but I mention this as a tool you could use or have someone do it for you, if you have concerns about the steel thickness anywhere.

Steel is inherently extremely strong, so a little bit of surface rust is generally not a structural issue.

Finally, to overcome my paranoia about dropping stuff on my deck and chipping the paint, I had my entire deck, cockpit, etc, covered with " decktread"....this is a 3/16" thick high grip material that can be purchased in sheets which you can cut to suit and glue in place. I used epoxy glue. The "decktread" can be purchased in a variety of colors.

On my boat I had stainless steel stanchions welded to the deck. On a long ocean voyage, where I had constant spray washing over the boat, the stanchion/hull weld would bleed a little rust. Though the s/s stanchions were welded on with s/s welding rod, there were some areas where the paint system allowed some micro sized rust bleeding. This was more a pain in the rear end than anything else, but on arrival at my destination, I would wash this off.

Like others on this thread, I would sometime use a dremel tool fitted with a metal burr, to clean up a rust spot before using the ospho, etc...

Hope this helps provide some guidance..
MicHughV is offline   Reply With Quote
Old 17-04-2020, 08:44   #39
Registered User
 
DeValency's Avatar

Join Date: Oct 2018
Location: Boston
Boat: Farr 40 (Racing), Contest 43 (Cruising)
Posts: 466
Re: What is the best way to prime steel?

I have a Dutch GRP made (yet, like steel...) boat but a good friend has a Jongert 72’ and we went together through some steel treatment projects. First, remember rust in steel boats start from the inside. - look carefully under the deck and along all areas especially the hatches, chain plates (or whatever it is) and other deck hardware mounts.
Only sandblasting works in peeping the surface! But be ready with the primer immediately.
I had a great experience with International Interprotect 2000E epoxy on my huge iron keel and wings overhaul last year. Looked solid bright and I hated to paint it with the anti fouling. - the finish was outstanding even with a roller but if you can power spray, you’ll get even better results, especially in tight corners and areas that are always more sensitive to rust. (The paint is very thick).
I would say at least four costs of the primer - follow the instructions very very carefully!
After that you should be good to go with any appropriate topcoat - verify that it works well with the primer - it is a known issue.

Enjoy!

Quote:
Originally Posted by chamoy View Post
Hi,
I just bought a 12m steel sloop build in Holland in 1985. No one knew what sort of paint system the boat has. Out on deck it seems like it has a light grey looking thin primer on top of the steel and then a very thick black layer of something very tough that looks like a primer and then paint. Rust is not a big issue, but there are a few places rusting out on deck that I have to tackle.
What is the advice of the experimented steel boat owners out there?
I have heard all sort of ways of doing it, like grinding the steel and 2 part epoxy primer, or sand blasting and 2 part epoxy primer, or just bit of a clean and a rust converter/primer, there is one called Brunox epoxy, that is supposed to by a 1 part epoxy rust converter/primer.
I appreciate any good tips,
Cheers!
__________________
New England offshore racing, Worldwide performance cruising - S/V GDY-Kids: 4/2020 back from the Caribbeans. 7/2020: temporarily docked in Savannah, GA.
https://www.instagram.com/gdykidscontest/
DeValency is online now   Reply With Quote
Old 17-04-2020, 09:24   #40
Registered User

Join Date: Jul 2011
Posts: 1
Re: What is the best way to prime steel?

I’ve had as steel boat on the water for 15 yrs and the best thing Ever that I used was MCU Coating’s Internationa’s, Miozinc primer, Miomastic intermediate coat and MCU topcoat. it’s a single pack moisture cured urethane that loves humidity, is extremely surface tolerant, can be applied over any other product with only fairing it in to achieve a smooth surface. Another advantage is it adhere’s to stainless (if you get it on your hands clean it off as soon as you’ve finished, because if it dries, there is no solvent that can remove it) so where I welded my staunchion bases, chain plates, etc, I just painted 1/2 an inch up the stainless and have never had a problem.
This product is used extensively in the petrochemical industry amongst others as it is acid resistant and extremely hard wearing and the Mcu clearcoat is totally UV resistant and will last for years
RodBan is offline   Reply With Quote
Old 17-04-2020, 09:53   #41
Registered User

Join Date: Mar 2013
Posts: 18
Re: What is the best way to prime steel?

I don't believe Coal tar epoxy has been outlawed. It appears to be readily available.
Google it or click on the link.
https://www.grainger.com/product/3XH...g!472573728668!
col50 is offline   Reply With Quote
Old 17-04-2020, 10:21   #42
Registered User

Join Date: Jan 2014
Posts: 930
Re: What is the best way to prime steel?

Quote:
Originally Posted by col50 View Post
I don't believe Coal tar epoxy has been outlawed. It appears to be readily available.
Google it or click on the link.
https://www.grainger.com/product/3XH...g!472573728668!

Thank you. I have read about using coal tar epoxy and wondered if it was still available.


Later,
Dan
dannc is online now   Reply With Quote
Old 17-04-2020, 10:34   #43
Registered User

Join Date: Jan 2013
Location: Tracys Landing MD
Boat: Grand Banks 46
Posts: 22
Re: What is the best way to prime steel?

I restored a 1951 Alden Steel Ketch.

The bilges were a mess. In a few spots I had to cut out and weld back in new hull plate.

The very good tool for preparing steel for paint is a needle gun.

The tool I used was a JEX-20 Needle Scaler. I used it for 10s and 10s of hours, went through a set of needles, and it was still going strong. And I sold it on eBay after I finished with it.

Worth every penny. Highly recommended.



https://www.mrmtool.com/Nitto-Kohki-...xoC1kAQAvD_BwE
jdecris is offline   Reply With Quote
Old 17-04-2020, 10:53   #44
Registered User

Join Date: Dec 2014
Location: Amsterdam
Boat: Blokland Steel 10m AftCabin
Posts: 8
Re: What is the best way to prime steel?

Quote:
Originally Posted by tasssos8 View Post
Hi there,

I live in The Netherlands and I have a locally made steel motorboat. The usual way treating steel here especially bellow the line is, primer, then, quite often, black Tenco bottom coat (as you described, thick and black) and then a couple of layers of antifouling.
You can treat the small rusted parts with Vactan. First wire brush but leave some rust on.Then apply a good layer of Vactan on it. That converts rust and it is a very good primer too. Then any oil based paint (or black Tenco bottom coat) over it and you are good to go. I just did my over the line repairs and soon I take it out to treat the bottom using the technique I described.

Good luck, those steel sloops are for ever!!!
I just found that Tenco does not go over primers!!!! I didn’t know that! That saves me a layer. At the end, a bronze Tenco layer as antifouling is the best to finish all off.
tasssos8 is offline   Reply With Quote
Old 17-04-2020, 11:00   #45
Registered User

Join Date: Mar 2013
Posts: 18
Re: What is the best way to prime steel?

Quote:
Originally Posted by ejjawhite View Post
TwoWords: Coal Tar
You do mean coal tar epoxy - right?
col50 is offline   Reply With Quote
Reply

Tags
steel

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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
Perkins Loses Prime Janice Engines and Propulsion Systems 18 01-04-2020 22:45
Prime Climb Mast Steps over40pirate Product or Service Reviews & Evaluations 23 28-07-2010 19:47
For Sale: Mast Climbing System by Prime Climb over40pirate Classifieds Archive 0 02-05-2010 07:11
NOAA-N Prime: "In Just a Few More Hours.... MV Off Topic Forum 1 04-02-2009 03:02
Genset pump prime problem The Mons Engines and Propulsion Systems 9 03-10-2008 17:49

Advertise Here


All times are GMT -7. The time now is 13:17.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.