Headhunter Posted May 17, 2023 Report Share Posted May 17, 2023 A little help please. We have platform welded to the boats cradle to fill the space between the dock and boat. Aluminum frame with 2x8 pressure treated lumber on top with rug on top of that. The maverick is in for service so I decided to replace the 2x8s. The 2x8 were attached to the frame with stainless deck screws. Over the last 8 years corrosion from dissimilar metals took its toll. I am thinking of going back with aluminum screws but is there another alternate? Any insight is appreciated. Quote Link to comment Share on other sites More sharing options...
jh141 Posted May 17, 2023 Report Share Posted May 17, 2023 Used on pontoon boats..... Xylan coated steel deck screws can be used in any environment and will not corrode. https://www.pontoonstuff.com/products/self-tapping-pontoon-deck-screws?currency=USD&utm_medium=cpc&utm_source=google&utm_campaign=Google Shopping&gclid=CjwKCAjw9pGjBhB-EiwAa5jl3K8xjouV6CAjEyfT3XYX3U-cWmV-eOby120Pu91gdwFyhdFVJaFDrRoCgAcQAvD_BwE 1 Quote Link to comment Share on other sites More sharing options...
George Seither Posted May 17, 2023 Report Share Posted May 17, 2023 Xylan coated fasteners work, used the application on sub sea service and loads of B-7 Flange Studs, Only other solution which I would not recommend is insulator kit on each screw/ stud. Quote Link to comment Share on other sites More sharing options...
whichwaysup Posted May 18, 2023 Report Share Posted May 18, 2023 That pressure treated lumber may also be a factor - I know that some pressure treated lumber used on boat bunks reacts badly with aluminum boats, causing pinholes and other issues. Could that be a contributing factor? https://www.ehow.com/how_7844027_stop-corrosion-caused-treated-wood.html Quote Link to comment Share on other sites More sharing options...
Headhunter Posted May 18, 2023 Author Report Share Posted May 18, 2023 Thanks guys for the invaluable information. My local bolt guy had the Xylan bolts so I'll give them a try. Which, I looked at the lumber link and determined that is not the case here. The corrosion itself on the aluminum channel was circular in shape with the screw in the middle of the circle. Boat will be home tomorrow so its time to get to work. 1 Quote Link to comment Share on other sites More sharing options...
SCFD rtrd. Posted May 20, 2023 Report Share Posted May 20, 2023 I would never attach any treated wood to bare aluminum. Just look at any all aluminum trailer where they attach treated bunks to the trailer. The treated wood will eat up the aluminum bunk stands in one or two years. My best guess is that the old bolts acted like an antidote and accepted most of the electrolysis. I would always place an 1/8" of rubber or plastic between any treated wood and aluminum. Quote Link to comment Share on other sites More sharing options...
jh141 Posted May 20, 2023 Report Share Posted May 20, 2023 2 hours ago, SCFD rtrd. said: I would never attach any treated wood to bare aluminum. Just look at any all aluminum trailer where they attach treated bunks to the trailer. The treated wood will eat up the aluminum bunk stands in one or two years. My best guess is that the old bolts acted like an antidote and accepted most of the electrolysis. I would always place an 1/8" of rubber or plastic between any treated wood and aluminum. I agree, My trailer built in 2012 was before they were putting a plastics insulator between the bunk stand and the wood, The aluminum area that contacted the wood was eaten away. I put plastic insulators on top of the bunk stands and stopped the erosion. Quote Link to comment Share on other sites More sharing options...
whichwaysup Posted May 21, 2023 Report Share Posted May 21, 2023 Dumb question, but could you use zinc anodes for this application? Quote Link to comment Share on other sites More sharing options...
HenrysCreek Posted May 26, 2023 Report Share Posted May 26, 2023 Curious to see some pics of your lift and platform as I’ve thought about doing the same. My MA is lift kept about 9 months of the year and it’d be nice to be able to get around to the outsides for service/cleaning. Any thoughts on how much weight the platform added? Not sure my lift will handle the boat, me and all of those 2x8’s (plus aluminum frames) Quote Link to comment Share on other sites More sharing options...
Headhunter Posted May 26, 2023 Author Report Share Posted May 26, 2023 Out of town for the weekend but will take some pictures when I get home. Quote Link to comment Share on other sites More sharing options...
Headhunter Posted May 30, 2023 Author Report Share Posted May 30, 2023 Here is the platform extension I renewed. I should have done some before and after and what the frame looked like but I didn't. It came out ok but if I have to do it again I would use 2x10s rather than 2x8s. 3 1 Quote Link to comment Share on other sites More sharing options...
George Seither Posted May 30, 2023 Report Share Posted May 30, 2023 Looks good to me Quote Link to comment Share on other sites More sharing options...
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