Centreboard Removal

[Peter T]

Hi All, have been busy today, While waiting on the galvanising of the trailer, and given that the lifting frame works so well, I thought it about time to remove the centreboard. With the boat hanging in the lifting frame with the bottom of the keel around 500 mm or more off the ground, I lowered the centreboard as far as it would go, was able from under the boat to lift it with no problems, so set it on a couple of jack stands and removed the pivot bolt which came out very easily. as I lowered the front jack stand, the centreboard was stuck in there but it was free enough to be able to swing it so I clamped a "G "clamp onto the centreboard and tapped it lightly downwards. didn't take too much to lower it enough to be able to remove what looks like two large washers made from Laminex or something similar. Once I found that I could take its weight on my own, removed the jack stands and now its out. Just Like that! easy. The galvanising on it looks ok for the most part but all the leading edge and the front sides are badly rusted So ai think I will make a new one. I reckon stainless would be the way to go but have no idea where I might get a 10 mm piece of stainless the size of the board? also, wont be cheap I wouldn't think. Anyway will make some enquiries I guess and see what eventuates. Bye the way, does anyone know what the bush for the pivot bolt is made from. It seems to be a really hard plastic or Bakelite or something similar See Pic's below

Oh, and bye the way, the centreboard will come out in the horizontal position, or any other angle for that matter. Cheers

Regards Peter T

[Peter T]

Well, am progressing with the centreboard quite well. The old one measured 12mm thick but it was hard to tell as parts of it were still galvanised and other parts was badly rusted. Anyway, when you galvanise steel, it adds 1 - 2 mm of thickness. Double that because there are two faces and this has lead me to use 10mm thick steel instead of 12. I had thought of making it out of 316 stainless steel but the cost ran out to around $1500. Because I intend to trailer my boat and not Leave it on a mooring, I believe that a galvanised steel centreboard will see me out so I was able to purchase a piece of steel flat bar 300mm wide and 10mm thick and cut to 910mm for $105, cheap I think. The actual size of the centreboard is 280 x 910 x 10 or 12 mm. The pivot bush is like a very hard plastic. It is actually called “ UHMWPE” Polycarbonate ( Polyethalone). I managed to buy a piece of 20mm round about 300 longvfor $7.00. So will be able to turn up the bush in my lathe and fit a new 316 stainless pivot bolt. The hole in the centreboard is more like 3/4 “ The large washers that go each side of the steel plate look like melamine or laminex or similar and are in good shape. I may need to use thicker but time will tell. I will fit it all after galvanising it once I have finished cutting it out. Will post photos as I go

Regards Peter T

[Ozzie]

Good reference material Peter, good luck with it all.

[Peter T]

Thanks Ozzie
Cheers
Peter

[snoopebj]

Good detailed photos Peter. Keep them coming. It’s a job I’ve been dreading. could be a job for lockdown take my mind off this chaos going around. My board has been stuck for years and I get rusty bits falling out occasionally ,maybe the whole damn thing will disintegrate and fall out eventually. I guess galvanizing methods have improved over the years.
Nice work and keep us posted.
Keep safe everyone.

[Peter T]

Hello Emery’s, had a bit of a spell on the centreboard as the trailer has taken over first place in my things to do list but all I now need to do to the trailer now is to modify the lights to make it legal and I will probably make new bunks as the old ones are a bit too narrow for my liking. Anyway, the new centreboard is half cut out so will get back on to that fairly soon. With yours, you will need a place to have the boat up in the air with all the centreboard case opening clear to get the board out. If it is stuck really hard, it might be passable toget a big pair of multi grips on to it and then use tools and levers to work the multi grips. If you can get the board to drop enough to have some of it show below the boat you could drill a hole in the board and fit a bolt so it can be pulled from there.
If you wanted to do a holiday to Tasmania, you would be most welcome to use my lifting frame to do the job if you wanted to, and then I could give you a hand but it would mean bringing your boat on it’s trailer to Tas, not a cheap exercise I wouldn’t think. Maybe there is somewhere close to you where you could do it? Might pay to ask around at some of the yacht clubs as to what’s available for you to lift the boat. I have read where it is possible to lay the boat on its side to do that job but I wouldn’t want to do that to my boat, way too much strain on the hull for my liking. Anyway, all food for thought.
Regards Peter T

[snoopebj]

Thanks Peter
As you suggest, failing your kind offer of using your frame in Tassie which would now involve 2 weeks of quarantine,. I'll enquire Brighton welding down the road to use his overhead crane. Let me know of the details of the galvanizing process on your board' and re-fitting method of bolt and spacers.
cheers

[Andrew]

I galvanised my centerboard and it cost about $50. The pivot bush was turned out of hard teflon like plastic by a local engineering firm. and i put some teflon like plastic side washers/spacers in to isolate it from the sides of centercase. (Details are in my blog "waterways" - centerplate tag)

Its worked well for the last few years and seems like the most economical restoration method.

[Peter T]

Thanks Andrew. Have been checking your blog out. Very helpful. Once the new centreboard is cut out and galvanised, we won’t re- fit it until all the fibreglass repairs have been completed.
I already have the material to manufacture the new bush which I will fit to the centreboard after galvanising it. That way, will get the perfect fit of the bush. My side large washers seem quite ok, so I reckon they will get another run, depending on the fit? My new board is out of 10 mm steel, not 12, so will be interesting to feel the fit inside the centreboard case.
Was thinking of 316 stainless centreboard, but as I am going to trailer my boat, I don’t see needing another centreboard being required in my life time, so I believe that galvanised steel will be fine. Also, that’s how they came new.
Regards Peter T

[Andrew]

Your centerplate isnt too rusted Peter, but good to get it out before it does. Mine was further advanced.. rusted under the side washers, the rust expanded and jammed it into the case, lots of "fun" to get free again. The longer they stay in there rusting, the more they could jam in there, and harder to remove..

reckon the hotdip galv plate should last me out. Always squirt the case out with freshwater hose to remove as much salt as possible after each sea trip, to reduce any corrosive action.