Under Mast Step Shimming Material?

[svmosaic38]

Ok, so I may have cut the bottom of my mast an inch or two too short. Now I'm wondering what type of material to lift the mast plate up with. My metal guy mentioned some composite material. Didn't sound like he had any 1" alum plating laying about. Grainger caries alot of plastic sheeting but it's rather confusing. Any suggestions on a high compression rated material that I can mill myself??

[zeehag]

i am having to shim my mizzen as there is an interruption in some of the integrity of it---and a wet bilge-- i also have a concrete ballast situation going on--that is ok--but the mast step and base are needing a support--so we are going to use a bi of steel and some wood and make a solid support --i can also use wood, as long as it is hard wood with no osmotic capacity---epoxy and shim. i will use wedges of wood--hard wood--under the mast and above the support/shim....
the mast will need to be raised a tad to slide these items under, and i have a hydraulic truck jack for that--we have a project and a few potential plans--good luck on yours--
if you have a metal mast base, add the shim under the base/step and have the aluminum sit on the wood support.

unless minaret has a better idea.....

[delmarrey]

I would go with G9 or G10 material. >>>> PHENOLIC

[svmosaic38]

thanks Zee. I should have mentioned that it is deck-stepped. The Mast is a Selden from a Hunter 41. They provide a nice sized aluminum foot to go underneath, only one hair larger than what Cheoylee provided. Thus far, I've not had to move either set of spreaders, nor the gooseneck. The payback was my poor measuring skills and not thinking that modern booms have a taller profile than wooden ones from 1978...
I'll take a look at the phenolic. Thank you both...BD

[zeehag]

i think, as this is mexico, that the steel idea is best and i have a dish of steel under my mast base--so it will work mebbe -and wedges of wood between the supporting steel and the base of mast--to keep it in position. should keep mine decent until i have a chance to drop mast and fix all the beams and bulkheads involved..could be a decent fix for the individual who is also looking for a decent fix...

[SV Demeter]

G-10 would be pretty pricey in those thicknesses but you can look here for some: www.mcmaster.com

I found a metal supply place here that had sraps of 1" -4" thick 6061 Aluminum plate. They sold to me a piece for about $75 that was 2" thick and 12" x 12". Company is called EJ Metals in Maryland. I would not use wood too soft. Either g-10 or make your own laminated FRP if Aluminum is not available. Steel will rust.

[svmosaic38]

Thanks SVDemeter, I looked up E-J MetalsToGo in Glen Burnie. Turns out they have alot of aluminum on Ebay, at pretty fair prices too. Some of my family lives near there, so maybe I could save in the shipping somehow. After several days of going round and round, I decided aluminum was cetainly the easiest to procure and mill, even if I have to do it all myself. Why must I make every boat task so complicated and drawn-out??
Thank you for your time!!!

[SV Demeter]

Originally Posted by svmosaic38

Thanks SVDemeter, I looked up E-J MetalsToGo in Glen Burnie. Turns out they have alot of aluminum on Ebay, at pretty fair prices too. Some of my family lives near there, so maybe I could save in the shipping somehow. After several days of going round and round, I decided aluminum was cetainly the easiest to procure and mill, even if I have to do it all myself. Why must I make every boat task so complicated and drawn-out??
Thank you for your time!!!

No worries. I had to make a new shim for my boat as the old one was wood and there was sag at the deck. In my boat the shim goes under the compression post below decks. We used 2" 6061 and my machine shop friend milled down to 1 7/8. If you have someone close tell them to just go to EJ and look in their bins for a piece close to your demands. EJ will sell by the lb and then you just need to get it to you. EJ also does water jet cutting and if you had a auto cad file say dwg. or dxf. file they could make your shim. I used them to make new chainplates in 3/8" stainless and then just had to polish. EJ are really nice to work with too.

[delmarrey]

Originally Posted by SV Demeter

G-10 would be pretty pricey in those thicknesses

We have a guy here in the Lynnwood area that sells remnants. I myself only have a few rem's left from making backing plates. The stuff can be epoxied together to make thicker pieces.

The problem with aluminum at the bottom of the mast is it will corrode too and end up just like the mast, again.

[sww914]

Call boatyards to see if they have any G-10 remnants they can sell you. I bought my boat at a boatyard and when I re-stepped my mast they offered to sell me a 12" square for $30.00. It's amazing stuff, you couldn't hurt it with a nuclear bomb.

[SV Demeter]

No corrosion issues with 6061 aluminum. Deck stepped mast means no water in bilge ever. G-10 I great too but will likely be a lot more expensive. Also a pita to machine.

[neilpride]

Well this is a keel step mast we fix last month , 2 1/2 inches of epoxy and a mix of carbon and fiberglass on top of the original setup, strong like hell,, the boat is a c&c 42 landfall ...

[Brazil]

Nobody mention starboard. It seems to me it would be strong enough. Any toughs ?

[skipmac]

Had to cut 3" off the bottom of my mast due to the use of a steel step and resulting mast base corrosion, apparently a common Pearson problem.

I built a new step from UHMWPE (ultra high molecular weight polyethylene) purchased from onlinemetals.com Stuff is very strong, chemical resistant (in case of oil or diesel spill into the bilge). Not sure how it would work as a bearing surface so used a 1/4" sheet of 6061 Al plate over the UHMW under the mast.

[zeehag]

if aluminum corrodes so fast, then why is your mast made of aluminum?? it should last a a few years for ye.