Rust Treatment - Steel Yacht

[Sangsom]

Originally Posted by TOM

You poor thing , you will spend a large amount of time fighting rust . Steel boats are not great ..we are currently sailing around the world on one actually a very good one but no matter how good they are made and how good they are primed you will still get rust . the only way to go is AIR TOOLS .Arm yourself with a compressor and some lethel air weapons and go to war! You need Shiney steel almost white and a good epoxy primer anything less then GLEAMING WHITE STEEL is a waste of time.

TIME .....YOU can achieve in 10 minutes with air tools what will take you an hour with a wire wheel.

Good Luck.

www.byamee.com

Agree with most of what you say Tom, but steel is great! you can fix it anywhere, you can do it yourself (as you obviously have), and you can hit really hard things and still come out a winner!

[saben]

I agree wiyh Tom above post to a point, anything short of white sand blasted, not shiney but dull white will last a very long time if properly coated, Angle grinders with 60 grit? may be the next best final metal prep but they burnish the steel, you can see the scratch marks but the grooves are shiney, coatings don't adhere well to shiney. That being said sandblasting is not always feasible. If you're going after below the water line exterior it's a waste of time and materials to do any thing but sand blast unless you just want it to look pretty for a new buyer in the yard.

[conachair]

Originally Posted by saben

I agree wiyh Tom above post to a point, anything short of white sand blasted, not shiney but dull white will last a very long time if properly coated, Angle grinders with 60 grit?

Had good results as well. Though even with the metal looking perfect, on a nice hot day pour some ospho and watch it bubble and fizz as it reacts with rust which you really believed wasn't there.

[Honey Ryder]

check out a book by scott fratcher called "metal boat repair and maintenance". in it he will tell you that there are various treatments which he describes in detail, and he will tell you how long each treatment will last.

according to him the best way, as in longest lasting, is to blast it and then coat it with amerseal followed by amerlock epoxy.

i am in the process of doing this to the inside of my stell hull. i have an electric compressor which puts out about 14cfm and i feed it into a pressurised potblaster. i started usinf aluminum blast medium but am switching to iron silicate as it is a fraction of the price.

i have removed all of the loose flaky rust with wirewheels, scrapers, and then sprayed liberally with a strong phosphoric acid (up to 20 times). this was very labor intensive, and i have a feeling that the blaster would have taken care of all that very easily too, so if i was gonna do it again i'd just blast.

remember to have your epoxy sealer (much thinner than the paint, so it gets deeper into crevices and gives a good bas for the epoxy to adhere to) all ready to go because for best results you really need to cover the fresh streel within a few hours, preferably minutes, or else it starts to rust straight away.

also, the steel needs to be warm, but not hot. if it is a hot sunny day then the metal deck will get surprisingly hot and the paint will go off too quicky. i am hoping for a dry, overcast day to paint, where the moisture content of the air is not too high.

according to scott fratcher, if you do it this way then it will last a very very long time.

another tip, if you don't have any limber holes on your horizontals then get a drill and put some in. otherwise and condensation will collect on the sill and eventually break the paint and then the rust will start all over again.

i am going to glue some plastic spacers to the hull so that the insulation will stand off the hull by a 1/4 inch or so, which means the condensation will fall down into the bilge (through the limber holes).

the original furring strips were soft wood (unpainted). i'll either paint the new strips with oil based paint or i may go with plastic instead.

i really recommend the fratcher book. he explains it all very well.

as usual, the more time and effort you put into the prep, the better is the outcome.

i don't really want to rip out my interior and do this all again in 5-10 years so i'm gonna blast and then use the amerseal/amerlock paint system. they use it on the oil rigs so it must be pretty good.

good luck. it's a nasty job but done well it will last for years.

[conachair]

Originally Posted by Honey Ryder

check out a book by scott fratcher called "metal boat repair and maintenance". in it he will tell you that there are various treatments which he describes in detail, and he will tell you how long each treatment will last.

available for download here Metal boat maintenance-A do it yourself guide by Scott Fratcher in Engineering