5200 and aluminum

Ryan Werden

Ryan Werden

Well-known member
I have a couple of questions for the group.

1) I plan to install an aluminum backing plate in the splash well of my estuary. After each season is over, I take my motor off and store it in the garage until the Spring when I get the boat back out. I noticed after this season that the clamps have really left an indentation in the transom of the boat and even punctured the glass cloth in that area. So I plan to sand and reglass that in addition to the alum. plate. Anyway, I recall when Tod removed his keel guards a few years ago that the aluminum had corrosion where it was bedded with 5200. What would be the preferred bedding compound for this plate? I can help secure it with a screw in each end but plan for the majority of the holding power to come from the bedding compound.

2) My full canvas cover is in need of a good pressure wash and re-waterproofing. I bought some Canvak to take care of that. My question is, do you think this would be good to use on the cordura dodger too?

Thanks in advance,
Ryan
 
I have a couple of questions for the group.

1) I plan to install an aluminum backing plate in the splash well of my estuary. After each season is over, I take my motor off and store it in the garage until the Spring when I get the boat back out. I noticed after this season that the clamps have really left an indentation in the transom of the boat and even punctured the glass cloth in that area. So I plan to sand and reglass that in addition to the alum. plate. Anyway, I recall when Tod removed his keel guards a few years ago that the aluminum had corrosion where it was bedded with 5200. What would be the preferred bedding compound for this plate? I can help secure it with a screw in each end but plan for the majority of the holding power to come from the bedding compound.

2) My full canvas cover is in need of a good pressure wash and re-waterproofing. I bought some Canvak to take care of that. My question is, do you think this would be good to use on the cordura dodger too?

Thanks in advance,
Ryan
Click to expand...


5200 woudl be what I would use. Mine seperated after heavy saltwater use, the corrosion worked under them and worked them loose. No one else has ever complained about this from what I've heard. For freshwater use it wouldn't be an issue, I don't think. I replaced mine with 304 SS.

How big of a piece are you looking for?
 
Ryan,

Personally I would use the 5200. Remember that Tod operates in salt so corrosion is a foregone fact from what I understand. Either that or go with a stainless steel plate instead.

No experience with the waterproofing on Nylon.
 
Ryan:

A couple of thoughts...are you hunting in saltwater? Because of Tod's location and posted pics I'm guessing he uses his boat in saltwater and that's probably a factor contributing to his corrossion issues. Second, do you need to bed the aluminum plate in 5200? If I understand what you're doing I'm not sure that bolting/clamping the aluminum under the motor would require bedding at all. Just my two cents.

I don't have an estuary but I have similar challenges on my BBIII. I put a sacrificial piece of ply under the outboard clamps to protect the transom - but my motor is also bolted so we may have different set ups/needs. I hunt exclusively in fresh water.

Good luck.
 
Guess I should have sat back and waited for Tod to answer... at least we all agree!


Ryan, hopefully Tod will chime in, but what I remember is not the 5200 being his issue it was the Aluminum with the salt water he hunts. I think he changed to SS or Bronze.

I wrapped some SS over my mahogany motorboard on my sneakbox, because I did not want to bite into the wood/epoxy. I also installed an aluminum clamp plate I had gotten from David Clark. The clamp plate sits under the clamp screws, and really provide a nice positive location for the cups. Unfortunately the new Yamaha clamp is smaller than the old OMC clamp I build the motorboard based on, so I had to remove the aluminum clamp plate. I secured it with 2 SS screws that aligned under the clamp screw caps, so the hardware was hidden. I used 5200 full contact for the SS to the epoxy and for the aluminum to SS. It took a chisel to break the 5200 seal, but once I did, I was able to peel most of it off. I had not roughened the surfaces, so that might add some adhesion, but I was using the 5200 more as a seal, then a fastener.

In fresh water, I think you will be fine, though there maybe some galvanic action between the bolts and the aluminum, but it will last far long enough for you!
 
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5200 is used for these applications in thousands of boats - both salt and freshwater. I wouldn't be concerned about it. There is also a difference between corrosion and oxidation of the aluminum which is often mistaken for corrosion. not saying this is the case discussed here, just that many times one is confussed for the other.

Mark W


__________________________________________________

 
5200 woudl be what I would use. Mine seperated after heavy saltwater use, the corrosion worked under them and worked them loose. No one else has ever complained about this from what I've heard. For freshwater use it wouldn't be an issue, I don't think. I replaced mine with 304 SS.

How big of a piece are you looking for?
Click to expand...

Thanks Tod. How big of a piece of aluminum? I have what I need, but I'm going to have 1/16" milled off of the 1/4" plate that I have. Like Dave, my Yamaha has a 2 1/4" inside throat and I need a bit of clearance to slide the motor on once the plate is installed. My transom is 2" now.

Thanks again.
 
Ryan,

Personally I would use the 5200. Remember that Tod operates in salt so corrosion is a foregone fact from what I understand. Either that or go with a stainless steel plate instead.

No experience with the waterproofing on Nylon.
Click to expand...

Thanks Pete. Looks like I'll go with the 5200. I was thinking that the salt may have been a key contributor.
 
Ryan:

A couple of thoughts...are you hunting in saltwater? Because of Tod's location and posted pics I'm guessing he uses his boat in saltwater and that's probably a factor contributing to his corrossion issues. Second, do you need to bed the aluminum plate in 5200? If I understand what you're doing I'm not sure that bolting/clamping the aluminum under the motor would require bedding at all. Just my two cents.

I don't have an estuary but I have similar challenges on my BBIII. I put a sacrificial piece of ply under the outboard clamps to protect the transom - but my motor is also bolted so we may have different set ups/needs. I hunt exclusively in fresh water.

Good luck.
Click to expand...

Thanks Kev. I should have mentioned that I wasn't hunting the salt. The reason I want the bedding is that the splash well isn't very deep and I would like to have more bite than just a screw on each end of the plate. I do not have the motor bolted on, but it is secured to the boat with SS cable.
 
Guess I should have sat back and waited for Tod to answer... at least we all agree!


Ryan, hopefully Tod will chime in, but what I remember is not the 5200 being his issue it was the Aluminum with the salt water he hunts. I think he changed to SS or Bronze.

I wrapped some SS over my mahogany motorboard on my sneakbox, because I did not want to bite into the wood/epoxy. I also installed an aluminum clamp plate I had gotten from David Clark. The clamp plate sits under the clamp screws, and really provide a nice positive location for the cups. Unfortunately the new Yamaha clamp is smaller than the old OMC clamp I build the motorboard based on, so I had to remove the aluminum clamp plate. I secured it with 2 SS screws that aligned under the clamp screw caps, so the hardware was hidden. I used 5200 full contact for the SS to the epoxy and for the aluminum to SS. It took a chisel to break the 5200 seal, but once I did, I was able to peel most of it off. I had not roughened the surfaces, so that might add some adhesion, but I was using the 5200 more as a seal, then a fastener.

In fresh water, I think you will be fine, though there maybe some galvanic action between the bolts and the aluminum, but it will last far long enough for you!
Click to expand...

Thanks Dave. I bet I have the same plate as you. I'm going to take mine to a machine shop and have a 1/16" milled off the back. This will give me just enough to slip the motor on.
 
5200 is used for these applications in thousands of boats - both salt and freshwater. I wouldn't be concerned about it. There is also a difference between corrosion and oxidation of the aluminum which is often mistaken for corrosion. not saying this is the case discussed here, just that many times one is confussed for the other.

Mark W


__________________________________________________
Click to expand...

Thanks Mark. 5200 is what it'll be.
 
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