Keel Guards

What about PVC pipe--cut a lengthwise section. You could fasten it with screws and 5200, just like aluminum or stainless. a 1" width would have a slight convex
Rick
 
From my utility construction days with sewer and water pipe, I had considered using pieces of SDR-35 that come in 13' lengths. It won't just shatter because it's cold out, but I don't think it will hold up to the use/abuse a duck boat goes through. I think it would look kinda... well cheap, for lack of a better term.


On a quick internet search, I did find a place that sells stips of bronze and stainless (only 1' sections) and it looks like it's somewhere around 5'/ft. Maybe I can scrounge something up at the scrap yard around here. I'm debating just leaving well enough alone, and running this thing for a season without any guards as I have no idea what the previous owners did to wear through the glass down to the wood keelson.
 
I attached my salt treated 3/4 x 1" with silicone and used a polyethene strip over it. It leaked.
I had 2 -3/4 x 1 " white oak strips cut at woodworkers supply in Millsboro . I planned on sanding the bottom back down to glass, using the West systems 404 to bond them down. Once set I was going to remove the screws and fill the holes with the west systems 404 then glass over them with Kevlar. Any thoughts on this process??
Thanks Kevin for posting this, I have the same questions and concerns.
 
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Maybe you had bad 5200 Tod. 5200 has been used for years to bond lots of stuff to lots of stuff. I do have a couple of suggestions to make the bond better.

1. Scuff the surface like has been mentioned here.
2. Mist both surfaces to be bonded with water. The 5200 is a moisture cured urethane product and water makes it cure faster.
3. Don't encapsulate the bond. Many times product has been used to build transoms and then the whole transom is covered in fiberglass. Onoce covered, no wate can get in and with no moisture, there is no cure.

Hope this helps.

Mark W
 
Maybe you had bad 5200 Tod. 5200 has been used for years to bond lots of stuff to lots of stuff. I do have a couple of suggestions to make the bond better.

1. Scuff the surface like has been mentioned here.
2. Mist both surfaces to be bonded with water. The 5200 is a moisture cured urethane product and water makes it cure faster.
3. Don't encapsulate the bond. Many times product has been used to build transoms and then the whole transom is covered in fiberglass. Onoce covered, no wate can get in and with no moisture, there is no cure.

Hope this helps.

Mark W
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I wondered that, but I don't think so. It is all still on the strake and tough as nails (rubbery nails anyway) and perfectly intact , I'm sure it will be a fight to get it off to do the work I want to do. In the areas where there is pitting on the underside of the strip there is loose aluminumum oxide powder. It seems like it just ate its way loose and the aluminum ovide served as an ablative layer.
 
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From my utility construction days with sewer and water pipe, I had considered using pieces of SDR-35 that come in 13' lengths. It won't just shatter because it's cold out, but I don't think it will hold up to the use/abuse a duck boat goes through. I think it would look kinda... well cheap, for lack of a better term.


On a quick internet search, I did find a place that sells stips of bronze and stainless (only 1' sections) and it looks like it's somewhere around 5'/ft. Maybe I can scrounge something up at the scrap yard around here. I'm debating just leaving well enough alone, and running this thing for a season without any guards as I have no idea what the previous owners did to wear through the glass down to the wood keelson.
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A good metal yard will have everything you want, standard sizes seems to be 12' from what I've seen. I've used Yarde metals (do a search for a location near you), but your yellow pages should have something similar. You want flat bar (an FYI - rolled round edge is the way the edge is treated as compared to a square corner if you get someone on the phone and they ask you about it - either is fine), in stainless I think you want 302, 303, 304 or 316.
 
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Tod, Did you "wet out" both surfaces with 5200 when you set the keel guards in place?

The reason I ask is I have seen some horrific deformation of wood when the aluminum has corroded and compressed the wood under it as the fasteners held it down. I'm talking about soft woods mainly. One instance in particular was on an old Motor Life Boat that had aluminum hand rails installed. Where the uprights were bolted the compression on the canvas, white cedar whaleback was 2/3 the thickness of the cedar. (Two-3/8" lamination's.)

I started wetting out both surfaces in an attempt to remedy this but the jury is still out until enough time passes. That is why any and all observations on the subject are appreciated.

To be sure the problem lies less with the 5200 than with the aluminum and its "Creeping crevice corrosion" or whatever it is called.

Thanks,
Eric
 
Tod, Did you "wet out" both surfaces with 5200 when you set the keel guards in place?

The reason I ask is I have seen some horrific deformation of wood when the aluminum has corroded and compressed the wood under it as the fasteners held it down. I'm talking about soft woods mainly. One instance in particular was on an old Motor Life Boat that had aluminum hand rails installed. Where the uprights were bolted the compression on the canvas, white cedar whaleback was 2/3 the thickness of the cedar. (Two-3/8" lamination's.)

I started wetting out both surfaces in an attempt to remedy this but the jury is still out until enough time passes. That is why any and all observations on the subject are appreciated.

To be sure the problem lies less with the 5200 than with the aluminum and its "Creeping crevice corrosion" or whatever it is called.

Thanks,
Eric
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Eric, your input is appreciated. I did not apply to both sides, just the wood surface. I had a lot of squeeze out if I remember and I obviously have 100% coverage under the strip now that I can see it. Keelsons are oak and the corrosion was minimal, so no deformation fo the wood that I can tell. Really, if I wanted to I could polish these strips up and put them back on, the corrosion was that minimal, the loosing of adhesion is the thing that bothered me, although it really had no impact on the performance.

So the creeping crevice corrosion is a known thing, that is comforting in a way.
 
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Thanks for that Todd.

I'll keep my eye on the work we have done with the "wet out" method and see if it helps. To be clear when I say wet out I mean push it well onto both surfaces with a putty knife. Then you can put as much as you think you need to fill gaps before assembly.

Myself, I went with SS half rounds. Mainly cause I only wanted prices on same but my wife thought I wanted them so she ordered them. You can bet that when she did not bat an eye at the price I keep my mouth shut and went with SS. :^)

Aluminum will do some strange things under the right conditions. I think it is much like SS in that it needs to oxidize to retain its state. I'll have to go back to the books on that one.

Once again thanks Todd,
Eric
 
If anyone wants the technical contact at 3M who can answer any and all 5200 related questions, let me know and I'll pass along. Lot's of knowledge here on that product and I am certainly not the best technical guy to answer them. Let me know.

Mark W
 
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