Shotblasting iron keels

[Becky]

I know that my keels are iron, because they are coloured mottled rust-brown and antifouling-blue. I have been advised that they will need shotblasting, not just a rub down with a big sander with a very rough sanding disk, which is what I would have done, at least until my arms got sore. So, can anybody recommend someone in the Chichester area with the necessary equipment to give my keels a through clean up?

<hr width=100% size=1>

 

[Joe_Cole]

Sorry I can't. However, if you are going to the expense of getting the keel properly shotblasted it is important that you paint it immediately afterwards. Otherwise you may just as well continue doing what you are already doing.

Joe

<hr width=100% size=1>

 

[Becky]

Thank you for your advice. I agree that I wil have to cover bare metal as soon as it is exposed. But I seem to have found a man who may be able to help. Shotblasting among lots of other yachts out of the water seems or be unpopular. But he had a useful suggestion- grinding the keels to bare metal and then painting them at once. Isn't this where I began? Wonder how much ballast I will loose?

<hr width=100% size=1>

 

[Decrepit_Mariner]

Last spring, I had all the antifouling taken off using the Farrow system (see Yachting Press). This is a frachise that uses what I can only describe as "wet slurry". The keels were done at the same time. No other boat owners minded, because the operator built a plastic "tent" around the boat, and went inside. It was quite expensive - £400 for a 26' GRP boat.

However, as it's wet the keels began to rust as soon as the antifouling was off! I put on a couple of coats of propritary rust converter (from halfords - the type that converts the rust to an impermeable surface). Followed this up with several coats of International primer (after consulting International). Then anti-fouled. at the end of the season, a couple of rust spots from deep pits.

I've done it the other way with grinders and sanders - this was more effective.

<hr width=100% size=1>

 

[smeaks]

Any decent blasting firm will be able to shot blast your keels within the vicinity of other yachts using kit that restricts the dispersion of the shot discharge. If you are having difficulty finding someone try looking under Graffitti removal in the yell pages. Grinding your keels can be a bad thing because of stress induced and also materlial removed. I think blasting is the best option. A quick spray of primer would close the steel from the atmos prior to final painting.

cheers and rsgards steve

<hr width=100% size=1>

 

[smeaks]

Any decent blasting firm will be able to shot blast your keels within the vicinity of other yachts using kit that restricts the dispersion of the shot discharge. If you are having difficulty finding someone try looking under Graffitti removal in the yell pages. Grinding your keels can be a bad thing because of stress induced and also materlial removed. I think blasting is the best option. A quick spray of primer would close the steel from the atmos prior to final painting.

cheers and rsgards steve

<hr width=100% size=1>

 

[smeaks]

Any decent blasting firm will be able to shot blast your keels within the vicinity of other yachts using kit that restricts the dispersion of the shot discharge. If you are having difficulty finding someone try looking under Graffitti removal in the yell pages. Grinding your keels can be a bad thing because of stress induced and also materlial removed. I think blasting is the best option. A quick spray of primer would close the steel from the atmos prior to final painting.

cheers and rsgards steve

<hr width=100% size=1>

 

[smeaks]

Any decent blasting firm will be able to shot blast your keels within the vicinity of other yachts using kit that restricts the dispersion of the shot discharge. If you are having difficulty finding someone try looking under Graffitti removal in the yell pages. Grinding your keels can be a bad thing because of stress induced and also materlial removed. I think blasting is the best option. A quick spray of primer would close the steel from the atmos prior to final painting.

cheers and rsgards steve

<hr width=100% size=1>

 

[philip_stevens]

Contrary to what some others have posted, you do NOT have to coat the keels as soon as they have been sand/shot/slurry blasted to a shiny surface.

I had my Konsort keels sand blasted 6 years ago while I was away at sea (MN), and didn't get home again until two months after the job was done. In that time, a good amount of surface corrosion had started on the keels - just what NeutraRust 661 needed. I gave the keels two coats of 661 and applied antifouling over the top the next day.

Since that time, NO rust has shown through. The boat came out of the water this November for a survey for sale - no rust on the keels other than a few spots near the bottom edges, where she had grounded on stony bottoms.

NeutraRust as such, cannot be obtained in the UK now, but the same stuff is available from Screwfix Direct as a Rust Converter. Vol 73, page 47, D18770, £4.99.

Two other boats in the same yard as I kept the Konsort also used the Rust Converter last winter, and both have come out with no rust showing through.

If anyone wants to see the results, the boat is now in Gweek Quay Boatyard - Saffron.

Next winter I will be having my new boat keels sand blasted, and will use what was left of the big tub of 6 year old NeutraRust 661 - that had a shelf life of 2 years and still works on rusty metal.

<hr width=100% size=1>regards,
Philip

 

[ex-Gladys]

Rust converting is the way to go. There are two forms of iron oxide, ferrous oxide and ferric oxide. (Fe2O3 and Fe3O4) Can't remember which way round they are. Basically rust is one, and the iron surface keeps converting. When you apply a rust converter it changes the oxide to the other one which is black and inert and impervious

<hr width=100% size=1>Larry Botheras

Anderson 26 "Amber"

 

[ashanta]

Dont go to all the effort of sand blasting. Remove the antifoul with a good scraper (sanvik type are good, with tungston blade) Brush the loose rust off. Apply a good rust converter (theres many available in car accessory shops) and finally paint two or three coats of keel primer. Blakes and International sell them.
This way will save you time and money and won't upset the neighbours but more importantly will last longer.
Good luck
Peter.

<hr width=100% size=1>

 

[Joe_Cole]

Steve,

We heard you first time! /forums/images/icons/smile.gif

If you go back into your posts and "Edit" is still shown up on the top right, you should be able to delete some of your multiple entries.

Joe

PS Interesting to see that you graduated from "New User" to "Regular" in one fell swoop!

<hr width=100% size=1>

 

[smeaks]

BEING A MERCHANT SEAMAN YOU WILL APPRECIATE THE NEVER ENDING CHIPPING OF OLDER STEEL DECKS.........OK YOU MAY NOT HAVE TO EXCLUDE STRAIGHT AWAY BUT WHY GIVE THE OXIDE THE CHANCE?

<hr width=100% size=1>

 

[Heckler]

was involved with building offshore production platforms, spec was shot blast and coat within 4 hrs if i remember right.
grinding is an option, stress is a red herring, weight loss is not even worth considering.
bought a 4" angle grinder last year £18, beneteau wing keel, cast iron, quite few rust patches, the keel has a gel coat encapsulate but as soon as it is nicked the dreaded rust gets in. anyway used said grinder on just the patches, ground back to good metal thru the a/foul and gel coat, applied hammerite steel primer immediately, put a coat on the patches every week until i launched, approx 5 coats and then coated with vc tar offshore, again just the patches and then antifouled, pulled out this last november and had one small rust spot after a full season and that was one i probably missed
moral, dont need to strip all the keel, grinding is ok, and its a lot easier and cheaper to just to do what is needed
stu

<hr width=100% size=1>http://www.beneteau-owners-association.org.uk

 

[Althorne]

Listen to philip stevens he's been there, done it and is right. I used to own a shotblasting company before retiring and he's suggestions are as good as it get's.
The only thing you have to do is make sure that the shotblaster is sure of what material your keels are made of and ensures he does not use a blasting medium that will embed any rust or paint material into it's surface by too much pressure or the wrong shot. Under no circumstances use a spinning disc to clean it off this will certainly embed some material no matter how hard you try, it's not what you can see, it's what you force underneath that matters.

<hr width=100% size=1>

 

[iacle]

One method not mentioned in this thread is to use a needle gun. I hired one for a few pounds & it was very successful - took a while for my wrists to recover though!
A grinder isn't much use unless done regularly. If you leave it a few seasons, as I did, a hard surface 'crust' develops & all the grinder does is polish the surface of this. I tried chipping it with a hammer - very slow; then a blunt axe - better, but still slow, before hiring the gun. Followed up with a rust converter then a couple of coats of Primacon.
Probably not as good as blasting, but not far off & much cheaper

<hr width=100% size=1>Ian