Bunk Replacement

[PapaBB]

I float a 1986 22CC Hydra Sport onto a tandom/dual axle Magic Tilt trailer.

My boat, fully decked out + fuel I estimate weighs in at about 4000lbs.

Presently when boat sits on bunks you can see some slight deflection outward in center of bunks but I don't think enough to be concerned about.

I am considering replacing the bunks on my trailer soon. They are 3" x 10" x 10' Cypress Wood, that are mounted on their edge, but sourcing Cypress in my area practically impossible.....

My Plan 'A' is possibly using Pressure Treated Pine cut to same size,,,,, anybody know of any possible problems with that plan?? There seems to be some concern about galvanic corrosion reaction due to chemicals in the PT wood???

My Plan 'B' would be to use some local sawn Aspen wood, same size,,,,, which is more easy to get here??

I am wondering about these wood types and what would be the strongest/toughest for this purpose with least deflection against weight loading??

Any suggestions or options available instead of wood bunk materials,,,,, like aluminum I-Beams maybe???

Anybody have any advice or experience in this area??

 

[smokeonthewater]

Re: Bunk Replacement

is the wood getting rotten? the whole setup looks like new..... does that trailer have keel rollers? I can't see this "deflection" in your pics but it may just be an issue of adjustment... also understand that if the hull isn't perfectly flat, the bunks MAY need to flex a little to fit properly....

If the bunks are still solid and strong I don't think I'd change em but if they are rotten that's another story

 

[PapaBB]

Re: Bunk Replacement

Wood not looking ROTTEN but is starting to show cracks/splits on ends at least??? The bunks are still covered with carpet that I am about to remove, because I have put the thin teflon covering (yellow in photo) on top edge of bunks instead of relying on carpet. I think that removing the carpet will allow the wood to dry faster and hopefully prevent moisture being held that will promote rot??

I will have clearer idea of condition of wood when I remove carpet but I want to be ready to replace just in case there's a need to,, or at least know where to get the wood I need??

No rollers on trailer at all,,,, I float on amd off so boat settles flat (sort of) on bunks. The outward deflection in center of bunks is VERY minimal so hard to see from photo angle I posted. The deflection is not much of a concern to me anyway because as you say, they would conform to hull shape somewhat anyway. The only concern I would have about deflection would be that I replace with wood type strong enough to withstand the weight and that would NOT be more flexible so as to deflect too much???

I have just completed a major refit to my trailer, replaced; both axles, all new hangers and hardware, new crossbars, new bunk brackets, new U-Bolts, etc., so the bunks are the next on the list,,,,, totally making all substructure and hardware new... That's the reason for replacement consideration...

What did you think of maybe using aluminum I-Beams for bunks????

 

[smokeonthewater]

Re: Bunk Replacement

I think alum is a bad idea... too rigid... pretty much ANY type of wood will be fine I have 2x8 PT pine under my 28'er

If it IS deflecting to the point of being a problem, maybe the angle of the bunk needs to be adjusted to be better lined up with the force (down and out) it sees