Rusty keel - how do I clean it????????

[BAtoo]

Just seen my keel and the rust has become too much - always been a bit of problem but bodged it so far.
Decided this winter is the time to do it properly - options seem to be pay up and get is professionally blasted or do it myself using an air powered needle gun/scaler.
Any ideas how much to have it professionally done - keel is approx 1.3 x 1.5 m plus a 1.8 m torpedo on bottom -??
Anyone used a needlegun for this job - was it easy/difficult any problems with vibration??

TIA

 

[paul_williams]

i did mine with a needle gun, quite easy but the vibration was bad. i,ve made up a flail instead. several short lenghts, (about 3 inches) of light chain, welded to an sds drill bit, with nuts welded to the ends. as the drill spins the end of the chain strike the rust and break it off. probably not endorsed by the health and safety bregade, but effective. wear lots off ppe.

 

[Tisme]

Last winter I used a needle gun on my keel and was disappointed with it. I found it slow and inefficient and I ended up doing most of the job using an angle grinder with a wire brush.

It may be that the needle gun I hired wasn't very good, but I've not used one before so I had nothing to compare it with. It was a waste of nearly £50 (including the hire of the compressor)

Last time I did the job was in 2000 (when I used the angle grinder) and it was only lightly rusted when I did it last winter. I'll stick to angle grinding in future.

 

[davidwf]

Please when doing it with whatever method you choose, try to avoid letting the rust and dust settle on your neighbours boats.

I had a guy clean his keel off next to me one year, it took me days to get the rust and old antifoul stains off my deck.

He of course couldn't see what the problem was.

 

[prescott56]

Angle grinder and wire brush is cheapest, dirtiest, horribliest option...but you should use a low grit sander (40 grit) to get a reasonable key once rust is removed. wire brushed tend to polish.

I have just tried POR 15 painted over my rusty keel. Have used this stuff on many cars and vans and it sticks like S * 1 T.
Doesn't convert rust just seals it.
To early to say what teh outcome is but teh guys over at POR are pretty confident.
Let me know if you want more info.

Regards

 

[nct1]

I used a needle gun last year and found it removed the paintand loose rust very quickly, I wore thick gloves which reduced the vibrations to a reasonable level

I would use it again, you may need 2 sets of needles for the keel as they tend to mushroom at the end after a while

You will need to find another tool to get the keel shiney, but the needle gun is the quickest way I know of removing paint and loose rust

 

[oldsaltoz]

G'day BAtoo,

Assuming your keel is cast iron:

It is most important that the casting is coated very soon after cleaning as cast will flash rust, this means rust starts to reform only minutes after its exposed to oxygen.

Cast is porous and has many small voids in it, so the cleaning method should not fill these voids with contaminants, as with a grinding motion, contamination is spread into the voids. a needle gun will push contaminants into the voids.

Dry Blasting provides a stream of clean abrasive material and will penetrate and clean the voids.

Also note that blasting should be done to class 2.5, that's an even (no shadows) silver/grey finish and coated, note the first coat is best applied as soon as a section has been completed.

This means having a roller (long handle job about 80 mm wide) and apply first coat as soon as the blasting nozzle has finished a strip big enough for the roller to fit.

If you do a search on this site you will find many items that refer to blasting keels and also note that the majority of blasted jobs lasted many years.

I started using the above method over 12 years ago and have never had a problem.

I hope this helps.

Avagoodweekend......

 

[BAtoo]

Thanks guys for the info; I think I will get a quote for a shotblast then if it's too expensive the needle gun ill be given a go.........