Strake question....

Thanks folks, your answers help very much. No wonder the brass seemed like such a great deal compared to the runners I priced in the catalog. I guess I juxtaposed "bronze" and "brass" in my head.

Back to the drawing board. I'll check with my brass source to see about bronze and stainless steel prices. My guess is they won't be anywhere near as affordable as brass.

At this point, it seems like the best approach is to try the boat as is for a season, and to see how it goes.

I'm happy to hear that I don't have to sand down to bare wood in the event I do add metal. On the other hand, if there's a whole lot of abrasion, then the question of whether to sand it down may become moot anyway.
 
Just a thought to throw out for comment, How about a few layers of kevlar over the Keelsons? Especially if it comes in tape. Works for bullets ;^) To make it pretty, follow with a top coat of glass.

Well, would it be practical?

Scott
 
Thanks folks, your answers help very much. No wonder the brass seemed like such a great deal compared to the runners I priced in the catalog. I guess I juxtaposed "bronze" and "brass" in my head.

Back to the drawing board. I'll check with my brass source to see about bronze and stainless steel prices. My guess is they won't be anywhere near as affordable as brass.

At this point, it seems like the best approach is to try the boat as is for a season, and to see how it goes.

I'm happy to hear that I don't have to sand down to bare wood in the event I do add metal. On the other hand, if there's a whole lot of abrasion, then the question of whether to sand it down may become moot anyway.
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For a smallish boat like that you could face them with Ipe, which is a very durable, heavy wood. It is used for upscale decks, you should have some sort of quality lumber yard locally that will have it. I would think it would work great for that. Bed in 5200 and screw on.
 
Steve, I'd go with the brass half round fastened with silicon bronze or as a second choice ss screws. The hardened brass may be difficult to bend to any degree. It certainly would be worth considering though.

The important thing to remember is the wood should have a flat face to support the brass and not allow any "catch" edges. If your keelsons are 3/4" then 5/8" half round would be about right. The brass is a sacrificial protector. Bed them to the epoxy, not to paint.

The only reason I do not have brass on my boat is due to a miss communication between my wife and I. SS half rounds I can get from my regular distributors. Brass would have required a trip to the other side of the Island.

Aluminum may give you problems with creeping crevice corrosion and it is relatively soft. It is easy to work with though.

Eric
 
Tod,
As you have had corrosion problems with Aluminum you may have it again with stainless if you don't install a sacrificial zinc somewhere on your hull. electrolisis is a bear especially in salt or even brackish water. Also I too would go with B as the simplest solutions are frequently the best. Wash your boat bottom with fresh water after you use it in salt or brackish water, and of course your trailer too.
JMO,
Harry
 
As for wood,
white oak is the only Oak that should be under water for any length of time.
Red oak is not a boatbuilding wood as the open pore cell ends wick moisture in red and cause rapid rot. Other than black locust W Oak is tough as it gets.

I still like UHMW and I think the issue with the splits is related to the tapered hole and screw. A flat bottom hole and a pan head would be better.


SS will work and is strong. But you are still running on the rocks with it. Its going to get banged once in a while.
 
As for wood,
white oak is the only Oak that should be under water for any length of time.
Red oak is not a boatbuilding wood as the open pore cell ends wick moisture in red and cause rapid rot. Other than black locust W Oak is tough as it gets.

I still like UHMW and I think the issue with the splits is related to the tapered hole and screw. A flat bottom hole and a pan head would be better.


SS will work and is strong. But you are still running on the rocks with it. Its going to get banged once in a while.
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Bob,

When you have some time do some reading on Ipe, much denser than oak or locust and much much more wear resistant. It is a material like you have never seen in the natural world. A 4x4 x 10' feels like an iron bar in terms of weight, it si wood that does not float. John Catazone and I think Hank used it on their BBSB's as a sacrifical wear strip it is very cool wood.

As for UHMW, I respect your opinion a lot and I know you have experiance with it, but have you have used it in strips on runners? Unless you use a large piece ( greater than something like 1/2" x 1" miniumum) of it and bed it completely in epoxy or 5200 and run that bedding material far up the sides it will fail. It expands and contracts with temperature and won't fasten to the bedding compound. When it expands it will gap and dirt/grit will get behind it and compromise the the material underneath at least or break it off unless you put gobs and gobs of bedding compound way up the sides. Look at how Tolman does it - fastened mechanically and smeared with a huge epoxy fillet. That epoxy for sure doesn't stick to it, it just holds it in place so it won't shift and so grit can't get behind it. I don't see how a small strip of it on a keelson or strake like we are talking will function properly: it will gap and stuff will get behind it or it will not resist a lateral force because there is no place to put those bedding fillets.

T
 
Tod,
As you have had corrosion problems with Aluminum you may have it again with stainless if you don't install a sacrificial zinc somewhere on your hull. electrolisis is a bear especially in salt or even brackish water. Also I too would go with B as the simplest solutions are frequently the best. Wash your boat bottom with fresh water after you use it in salt or brackish water, and of course your trailer too.
JMO,
Harry
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Harry,

If not dealing with dissimilar metals, there is no need for a sacrificial anode. Stainless fastened with stainless can not galvanically corrode, the same with aluminum fastened with alumunum fasteners of the same series.

Not to say stainless can't corrode in saltwater, it can, but just because corrosion occurs, doesn't mean that it galvanic corrosion. Type 304 and 316, which are the typical marine alloys are extremely resistant to saltwater corrosion if exposed to the environment.

An interesting note is that you probably would not choose zinc as a sacficial anode to protect stainless steel if you had stainless fastened with something more noble (say like some gold screws), you would probably pick something like aluminum as an anode (cheaper and would last better).

T
 
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Tod,
I'm going with what all the pundits say and with personal experience. If you don't have something for those stray currents to attack they will attack something you don't want them to. This is regardless of the dissimalar metals issue as that is a different topic altogether. I have had to deal with both issues over the years and I hope you won't have to.

Still, wash the boat and trailer after use in anything other than clean fresh water. Of course careful washing will only impede corrosion, not completely stop it. Also even if the screws you use are the same grade of stainless it still might pay to bed them with a good marine sealant.

JMO,
Harry
 
No doubt on the 1\8 being too thin.
I would go no less than 1\2 thick as stated above on the UHMW. But SS will work too.
I think of any runner under a boat that is going to hit the beach as sacraficial.
If you cut enough ice or land on the rock\ sand enough times you will take out any of the above choices. But what I like about the UHMW is that you can skid your boat over the concrete or asphalt and it slips. SS will not be as easy to push\pull. If the UHMW breaks it will come apart at a screw hole most times. But SS if it gets going is gona rip some stuff up. I just got done doing an emergency repair on a 46 footers teak Rail\combing after the SS caught on a pile at a fuel dock and ripped out screws and stanchions for about 10 feet this sunday.
With the UHMW bedding is required but 5200 works and will give good service. If it wears or gets buggered do it over.... for me its the cost of using the boat hard. Baby it and you wont have to.
Don't get me wrong. SS will work fine and I think you will like it... but no runner is going to be forever. On these small boats flipping it and glueing on new wood, after you power plane off the old down to the hull, and whatever you want to cover it in, after a hard couple of seasons, just dosnt seem like that big a job for a work boat.
Not like chipping and painting a steel hull anyway.
This is not intended to change your mind, Only to provide information to others who may read this in the future and want to know about the options.


As for Ipe I have some in the shop, but..... I did a good portion of my undergraduate work on forestry and I like to stay local when it comes to wood if its for me. One of the graduate student instructors was from Nicaragua and he was still cataloguing South American Species in the early 90's. White oak is available and not expensive if bought in the rough. It also is the traditional underwater staple. Too heavy for planking but frames and dead wood were white mostly. Some Live oak but only on big dollar boats that could make a lot of money at their work. With all the things going on (Like Asian Long Horn Beetles) I support New England Wood Products where ever I can.
Thats just me and your milage may vary.
 
Just to throw this into the discussion, What about using Scott's drawing but replacing the SS channel with a piece of UHMW milled to fit over the White Oak? The sidewall of the UHMW would not need to be angled. Dimensions could be adjusted as seen fit. A couple passes across a table saw set up with a dado blade would make short work of milling the groove in the UHMW.

View attachment keelsoncovermod.jpg
 
Well, the IPE or white oak sacrificial wood strip sounds like a good approach. This is especially so for me, as I've spent the last 8 months learning how to work with wood and epoxy, but know very little about working with metal.

By the way, is IPE the wood's species, or are those initials that stand for something?

Thanks for all the help.
 
Well, the IPE or white oak sacrificial wood strip sounds like a good approach. This is especially so for me, as I've spent the last 8 months learning how to work with wood and epoxy, but know very little about working with metal.

By the way, is IPE the wood's species, or are those initials that stand for something?

Thanks for all the help.
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Ipe, is pronounced "e-pay", it is a group of tropical species used for decking (so the name for a group of species). Call your fanciest lumber yard in the area, I have several around me that carry it. Density and ultimately strength of ipe for that application is almost double white oak, so eventhough white oak may be the best local wood (barring some nasty species without straight grain or adequate size) ipe would be great for a smaller boat as an alternative to metal of some sort. It will dull your tools fairly quickly if used a lot due to its density, but you don't need to do more than rip a couple strips.
 
No doubt on the 1\8 being too thin.
I would go no less than 1\2 thick as stated above on the UHMW. But SS will work too.
I think of any runner under a boat that is going to hit the beach as sacraficial.
If you cut enough ice or land on the rock\ sand enough times you will take out any of the above choices. But what I like about the UHMW is that you can skid your boat over the concrete or asphalt and it slips. SS will not be as easy to push\pull. If the UHMW breaks it will come apart at a screw hole most times. But SS if it gets going is gona rip some stuff up. I just got done doing an emergency repair on a 46 footers teak Rail\combing after the SS caught on a pile at a fuel dock and ripped out screws and stanchions for about 10 feet this sunday.
With the UHMW bedding is required but 5200 works and will give good service. If it wears or gets buggered do it over.... for me its the cost of using the boat hard. Baby it and you wont have to.
Don't get me wrong. SS will work fine and I think you will like it... but no runner is going to be forever. On these small boats flipping it and glueing on new wood, after you power plane off the old down to the hull, and whatever you want to cover it in, after a hard couple of seasons, just dosnt seem like that big a job for a work boat.
Not like chipping and painting a steel hull anyway.
This is not intended to change your mind, Only to provide information to others who may read this in the future and want to know about the options.


As for Ipe I have some in the shop, but..... I did a good portion of my undergraduate work on forestry and I like to stay local when it comes to wood if its for me. One of the graduate student instructors was from Nicaragua and he was still cataloguing South American Species in the early 90's. White oak is available and not expensive if bought in the rough. It also is the traditional underwater staple. Too heavy for planking but frames and dead wood were white mostly. Some Live oak but only on big dollar boats that could make a lot of money at their work. With all the things going on (Like Asian Long Horn Beetles) I support New England Wood Products where ever I can.
Thats just me and your milage may vary.
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Bob, I didn't know you had an interest in forestry, neat. My minor for my PhD was in forestry. One of these days you are going to have to build a boat with the UHMW runners so you can teach every one here how it is done.

Best,

T
 
Tod, you are missing the easiest fix of all. Hard plastic rubrail like that found at Hamilton Marine in Portland Maine. 8 years ago when Frank Kehoe and I built my Snow Goose, we installed 3/4" thick by 1.5" wide hard plastic rubrails onto the keel and both keelsons. This rubrail was installed into mahogany approx 1.25" thick by 2" wide with bronze screws bedded with 5200. 8 years have gone by with no wear in rocky, zebra mussel infested Lake Champlain.

Installation is easy. You buy it in 40' rolls, you lay it out in the sun so that it relaxes, you straighten it out, and cut it to length. Trim the ends into a bevel shape (with a big honking file/rasp) so that the leading edge won't grab anything, drill the screw holes with a countersink bit, bed with 5200 and give the 5200 a day to cure.

Having gone this route once I would use this method/material again in a heartbeat.

John Bourbon
 
Tod, you are missing the easiest fix of all. Hard plastic rubrail like that found at Hamilton Marine in Portland Maine. 8 years ago when Frank Kehoe and I built my Snow Goose, we installed 3/4" thick by 1.5" wide hard plastic rubrails onto the keel and both keelsons. This rubrail was installed into mahogany approx 1.25" thick by 2" wide with bronze screws bedded with 5200. 8 years have gone by with no wear in rocky, zebra mussel infested Lake Champlain.

Installation is easy. You buy it in 40' rolls, you lay it out in the sun so that it relaxes, you straighten it out, and cut it to length. Trim the ends into a bevel shape (with a big honking file/rasp) so that the leading edge won't grab anything, drill the screw holes with a countersink bit, bed with 5200 and give the 5200 a day to cure.

Having gone this route once I would use this method/material again in a heartbeat.

John Bourbon
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John, I have the stainless all drilled and countersinked for my boat, so not a decision anymore. I thought of you and the PVC from Hamilton, I even called them for a shipping quote. Maybe I'm hard on the boat, tides put more wear on the boat than an inland boat if you like to hunt tight like I do (the front 1/3 of my keel is ground to heck). With the tides, you just get set up perfect and the tide lurches out and 5 minutes of indecision ends up with you partially grounded on barnacle covered sharp rocks. I wanted more wear resistant tham the aluminum I had. The PVC wouldn't be the best on my boat additionally since I went oversize on the strakes (on Sam's suggestion?) and the 2 and 3" wide strakes would take a pretty big piece to cover.

As for Steve's, boat or general use, the PVC would be a great option. Not expensive, great to work with if it is like the other PVC I've used. Steve, if you look at Hamilton marine, be sure to look at the "rigid" PVC, I 'm pretty sure that is what John used.
 
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Thanks for all the help (and with the pronunciation of the Ipe; that should help me appear to be less of a fool at the lumber yard).

I may purchase some Ipe now, rip a few strips, and just keep them in the garage as a backup or for repair materials if the present arrangement wears out.

May also have to print this thread for future possible reference.
 
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