Looking for sources to fabricate a steel centerboard

[DeanP]

I'm looking for someone to build the steel centerboard for my Beg-Meil project. The plans call for 12mm (~1/2") thick 316SS or galvanized steel. The dimensions (in millimeters) are shown below. I'd like to find someone who can both cut the basic shape and add a tapered trailing edge and round the leading edge (an airfoil of sorts). I can provide a CAD file for both the shape shown below and the "shaped" foil. I'd like to find someone within a few hours drive of Massachusetts so I could pick up the completed part.

Any recommendations/referrals would be most appreciated.

Thanks,Capture.jpg

[willin woodworks]

A quick Google of "Steel Fabricator Bolton Mass." turns up almost a dozen contractors in your area.
Any fab shop will cut out the basic shape but adding the foil is going to cost you..

[John Meachen]

If you can provide a dxf file of the outline (with all entities joined!) it wouldn't take long to cut the outline with a CNC plasma machine.It gets a bit more challenging when you need the edges cut to a profile.I'm pretty sure galvanised will be a lot less expensive than SS.

[DeanP]

A quick Google of "Steel Fabricator Bolton Mass." turns up almost a dozen contractors in your area.
Any fab shop will cut out the basic shape but adding the foil is going to cost you..

Hi,

I've done the google thing. I'd like to find a referral for a company that has some experience working on small, one-off jobs. While the local guys you reference have the advantage of being very close, I have no experience with any. The websites indicate their expertise/market is architectural weldments. As John mentioned in his post, CNC plasma (or water jet) would be the cheapest path to the 2D shape but none of the websites I visited indicate these companies have such equipment.

If you can provide a dxf file of the outline (with all entities joined!) it wouldn't take long to cut the outline with a CNC plasma machine.It gets a bit more challenging when you need the edges cut to a profile.I'm pretty sure galvanised will be a lot less expensive than SS.

Hi John,

I can provide a clean .dxf file. I agree, it would be fast to cut the profile with a CNC plasma cutter assuming the table can accommodate the part. I, too, am concerned about the cost machining the profile, but I would like to get costs for both. Similarly, I would like SS, but may have to settle for steel.

Thanks,

[pez_leon]

One thought: when I was considering building a Stir Ven 19, I asked Mr. Vivier about installing a wooden centerboard in lieu of the specified steel board. He was quite positive about it. If the costs for a profiled metal board are more than you want to pay, you might consider asking him about the performance penalty for a wooden board.

Keep us posted on what works!

James

[coelcanth]

try these guys for a baseline quote:
https://sendcutsend.com/

i don't think they would do any shaping, but you could do that with a file and some time..
maybe a grinder to start with, if you're in a rush

[Woxbox]

I would have a shop provide the steel -- not stainless -- and cut out the shape for me and then grind the edges and drill the holes myself. It's not all that much work, and you'll get it as you want it. Then take it out for galvanizing. Or, if this is to be a trailered freshwater boat, the right combination of rustproofing undercoat and topcoat will work quite well. I did a centerboard this way for a trailer boat decades ago. I never had a serious rust problem.

[JimConlin]

I would consider aluminum instead of stainless steel or galvanized steel.
Reasons:
You’ll be shocked at the cost of stainless.
You might find a steel fabricator easily enough, but getting the part galvanized is likely to be harder.
Grinding a shape into an aluminum board will be easier than steel and much easier than stainless.
The weight of the board doesn’t really add much stability but it certainly adds to the boat’s weight and makes it slower.

[Mark0]

Could it not be done with some form of composite construction ? Putting a foil on metal would be a pain. Foam or wood, not so much !

[MushCreek]

Getting the 2D shape should be easy; to do the shaping, you'd need to find someone with a big CNC machining center. Shape one side, flip it over, and shape the second side. The blank likely won't lay flat, so a couple construction holes might be required, and then plugged and welded after the fact. Probably not cheap, though. I'd probably do as others said- have the 2D shape cut out, and then go at it with a grinder. Before committing to steel, make sure you can find a shop to galvanize it afterwards.

[DeanP]

I would consider aluminum instead of stainless steel or galvanized steel.
Reasons:
You’ll be shocked at the cost of stainless.
You might find a steel fabricator easily enough, but getting the part galvanized is likely to be harder.
Grinding a shape into an aluminum board will be easier than steel and much easier than stainless.
The weight of the board doesn’t really add much stability but it certainly adds to the boat’s weight and makes it slower.

Could it not be done with some form of composite construction ? Putting a foil on metal would be a pain. Foam or wood, not so much !

Interesting. I had not considered anything but steel. I agree aluminum would be cheaper to cut, but it would weigh about 1/3 of the steel part (composite would be even lighter). James had a similar suggestion in Post #5. I had assumed the designer selected steel for the righting moment from the weight. Perhaps, I can check with Francois Vivier on any impact of having a much lighter centerboard.

Thanks,

[willin woodworks]

Why not a wood board with a lead insert? Cheaper, quicker, easier and more fun.

[DeanP]

Getting the 2D shape should be easy; to do the shaping, you'd need to find someone with a big CNC machining center. Shape one side, flip it over, and shape the second side. The blank likely won't lay flat, so a couple construction holes might be required, and then plugged and welded after the fact. Probably not cheap, though. I'd probably do as others said- have the 2D shape cut out, and then go at it with a grinder. Before committing to steel, make sure you can find a shop to galvanize it afterwards.

The flatness issue is a good point. I will have to add a flatness requirement to the part to ensure it doesn't get hung up in the well as its lowered or raised.

try these guys for a baseline quote:
https://sendcutsend.com/

i don't think they would do any shaping, but you could do that with a file and some time..
maybe a grinder to start with, if you're in a rush

Thanks for this lead! I will prepare a DXF for the profile of the board and share the pricing.

[Clinton B Chase]

I sent you a PM, Dean

[DeanP]

I sent you a PM, Dean

Hi Clint,

No PM found. Please re-send.

Thanks,

Dean

[Gary Davis]

I built a Beg-Meil from a Chase kit maybe 10 years ago. I had a local metal fabrication outfit, whose owner we knew, cut and shape the stainless CB. $1,000.

[StevenBauer]

$1000 doesn’t seem too bad. I just looked online and 1/2”x2’x4’ 304 stainless is about $1500 now.

[Clinton B Chase]

It's going to be more than $1,000 now!

[Canoeyawl]

Why not a wood board with a lead insert? Cheaper, quicker, easier and more fun.

This ^
and you can make the board a bit thicker with more shape ( better)

[Matt young]

This ^
and you can make the board a bit thicker with more shape ( better)

And it only needs the lead if the NA says it’s required. Otherwise you can do internal low fixed ballast and a line to hold the board down. I am a fan of well shaped boards, they can be made from well laid up lumberyard material.

[stromborg]

Why not a wood board with a lead insert? Cheaper, quicker, easier and more fun.

I tried this route twice with Marianita's bilgeboards and now have a set of as-designed steel plates weighing close to 100 pounds each.

The first set came in at about 60 pounds each and necessitated a much thicker slot than Iain Oughtred intended. Between the thicker board and slots, lots more drag than intended. Round two I reduced the wood thickness and increased the lead, better but the ply and lead didn't stick together very well, one of the boards popped enough that it got stuck in the 50% down position. No good for getting it back on the trailer. Trying to get enough lead in there to approximate the designed board and not have it be ridiculously thick is harder than it first appears.

I don't buy "the weight of the board doesn't matter much" argument. With the steel plates hanging down the boat is much more stable than when they are tucked up the their slots. Deployed and sailing the boat feels more stable than it did with the old lighter boards too. Beg Meil is what, 600 pounds? The board is around 90 pounds so not an insignificant part of the total displacement.

These are just my observations from messing around with my boat over the years. YMMV

[willin woodworks]

I wouldnt make a ply board without glassing it. I'd resaw a flat sawn or VG plank and flip every other piece end for end and drift and glue it together. I'd CPES it and epoxy coat it. I'd cut a hole in it with a hole saw and undercut the edges with a dovetail bit. Sheet lead hammered flat and alternating layers of epoxy to fill it up.
Paint it with Rustoleum rattle can marine enamel.

[pez_leon]

I suspect that, with the centerboard case already built, the total thickness of your centerboard is limited to the designed 12 mm. This may remove some of the possible advantages of wood construction - you just can't fit much of a NACA profile into something with that thickness-to-chord ratio. If you're interested anyway and want to read some smart people on foils and see my attempts to implement their ideas, check out page three of my build:

http://forum.woodenboat.com/showthre...lifornia/page3

Edit: Yes to fiberglassing. Rather than sheet lead, I'd suggest potting recycled lead shot in epoxy.

[stromborg]

Potting lead shot is okay, but no where near the density of solid lead, the epoxy between balls doesn't weigh much.

Having been down this rabbit hole, I'll stand by the idea of just getting it cut from steel sheet. I would think that a shop capable of doing the cutting would know where to get it galvanized as well.

Mine have been primed and top coated with a product that is supposed to be good...I haven't pulled them out yet but they seem to be holding up well, at least what I can see of them underwater. I'll give a more comprehensive report when I know more.

[DeanP]

I suspect that, with the centerboard case already built, the total thickness of your centerboard is limited to the designed 12 mm. This may remove some of the possible advantages of wood construction - you just can't fit much of a NACA profile into something with that thickness-to-chord ratio. If you're interested anyway and want to read some smart people on foils and see my attempts to implement their ideas, check out page three of my build:

http://forum.woodenboat.com/showthre...lifornia/page3

Edit: Yes to fiberglassing. Rather than sheet lead, I'd suggest potting recycled lead shot in epoxy.

You are exactly correct. The centerboard well was one of the first assemblies constructed. I will be forever stuck with a 12mm centerboard. I agree there is not much thickness to profile. I think, if I do anything at all, I may add a bullnose to the leading edge and maybe a 4-6" taper to a 1/8" trailing edge. Thanks for the link to work of others. I will review it. Cost may drive me to aluminum. We'll see what the quotes show.

[Woxbox]

The last time I had a piece fabricated, they recommended powder coating. This was easy to have done locally and is does provide a tough finish. Not to say that it's better than galvanizing, but it might be worth considering.

Also, I wonder if the CB case has been built yet. If it has, it's too late to switch to wood or glass, which would be double or more the thickness of a steel plate.

[jpatrick]

I’m pretty sure that aluminum will cost more than steel. I don’t know about galvanizing. Painting aluminum is always. Problematic.

Jeff

[sp_clark]

Aluminum will (perhaps) be easier to fabricate, at least for the shaping of parts. Spendier than steel? Yes, unless Stainless is your choice. And Aluminum’s less dense as well so equal volumes of metals will leave steel weighing 2-1/2 times more than aluminum.

Coincidentally I’m currently working to embed a ten pound lead brick in the daggerboard for my Waterlust canoe:

5FE6FC50-6DAD-486B-9434-9DB3CE51CDA0.jpg

Going out unballasted can be exciting owing to her design capability for 400#’s of ‘expedition’ kit I rarely if ever will have aboard. She needs ballast for more predictable stability when the wind’s up.

[cyclone]

Northwind Iceboats in Hanover MA may be able to do some small scale custom steel fabrication.

[A_Bluenoser]

For price context I got a similar centreplate made for an Ebihen 18 in Nova Scotia earlier this year (build thread to follow when I actually am able to start working on the build) from a local fabricator. It was 1" 316 Stainless, CNC Plasma cut, and the fabricator also did the aft chamfer, some rounding on the front, and drilled the necessary holes. I will probably do a bit more shaping on the front but on the whole it was pretty good. The total cost for that was a bit north of 5000.00 CAD of which more than half was the cost of the steel. I imagine you can get it a bit cheaper in the States, even taking the exchange rate into account, but it will be pretty pricey.

I think for some of the Vivier designs the steel centreplate is actually an important part of the ballast. For the Ebihen 18 (which is heavily water-ballasted) it is about 1/5th of the (full) ballast by weight so I expect making it out of something lighter would change the characteristics of the design quite a bit. In fact one of the design revisions for the Ebihen 18 was to make the centerplate trunk 5mm wider specifically to increase the centreplate weight. I would certainly check with the designer before changing it for something lighter.

[DeanP]

Northwind Iceboats in Hanover MA may be able to do some small scale custom steel fabrication.

Thanks for this lead. I will reach out to Northwind.

Regards,

[DeanP]

For price context I got a similar centreplate made for an Ebihen 18 in Nova Scotia earlier this year (build thread to follow when I actually am able to start working on the build) from a local fabricator. It was 1" 316 Stainless, CNC Plasma cut, and the fabricator also did the aft chamfer, some rounding on the front, and drilled the necessary holes. I will probably do a bit more shaping on the front but on the whole it was pretty good. The total cost for that was a bit north of 5000.00 CAD of which more than half was the cost of the steel. I imagine you can get it a bit cheaper in the States, even taking the exchange rate into account, but it will be pretty pricey.

I think for some of the Vivier designs the steel centreplate is actually an important part of the ballast. For the Ebihen 18 (which is heavily water-ballasted) it is about 1/5th of the (full) ballast by weight so I expect making it out of something lighter would change the characteristics of the design quite a bit. In fact one of the design revisions for the Ebihen 18 was to make the centerplate trunk 5mm wider specifically to increase the centreplate weight. I would certainly check with the designer before changing it for something lighter.

Thanks. This is a great data point. If I assume the material cost of the $5K would be half for me as the thickness of the Beg-Meil board is 1/2", and I assume the exchange rate is .75, the price for my centerboard may be almost $3K. That still seems ridiculous, but I may just need to be better calibrated to the current reality.

[Garret]

A shop in Hinesburg, VT could for sure do the basic shape & probably any bevels. They've done a lot a "interesting" projects - including oddly shaped stainless water tanks for my boat.

Giroux Bros. is the name - talk to Steve. You could tell them Garret Mott sent you, but you'll get "Oh s*** - this'll be something weird" along with en eye-roll & grin. Their grandfather started the business as a wagon works & wheel wright shop.

[A_Bluenoser]

Thanks. This is a great data point. If I assume the material cost of the $5K would be half for me as the thickness of the Beg-Meil board is 1/2", and I assume the exchange rate is .75, the price for my centerboard may be almost $3K. That still seems ridiculous, but I may just need to be better calibrated to the current reality.

Yes, prices have gone up substantially over the past couple of years. When I got mine this spring I was told that had I ordered it a year earlier the materials would have cost about half as much and that they were not able to issue quotes valid for more than a couple weeks because the price of steel was so unstable. I think things have calmed down a bit by now and I expect things are a bit cheaper in the States (they always are) but I would still expect to pay a lot more than even a year ago.

[John Meachen]

I'm horrified by these prices.I'd definitely go galvanised and if it meant burning out a couple of cheap angle grinders along the way,I'd accept that.The concave curves might be a good place to use a limpet drill to cut a series of holes for the grinder to remove irregularities from.