Replacing bunks. 2x6 or 2x4?

[bjennings79]

I've removed the crappy composite 2x6 bunks that were on my trailer and am ready to buy some 20' treated lumber to replace them with. A lot of the trailers that I've seen only use a 2x4 for the bunks rather than a 2x6. Is the 2x6 necessary? Also, are galvanized carriage bolts preferable over lag bolts for this application?

 

[coastalrichard]

Re: Replacing bunks. 2x6 or 2x4?

Your decision will be governed by the distance of your bunk span between fasteners. If your bunk supports are more than 36" apart I suspect you'll want to stick with the 2x6

 

[a1nowell]

Re: Replacing bunks. 2x6 or 2x4?

bj79,
If you had 2x6 before I would go back with 2x6. But DO NOT use treated, the chemicals in the wood are corrosive to your aluminum toons. Covering treated wood with carpet does not work because the chemicals leach thru the carpet. I would use untreated wood or if you use treated the separate the wood from the toon whit bunk slicks like in the site listed below. Those are what I used after finding out too late about the treated wood and aluminum.

Larry

http://www.wholesalemarine.com/p/T-D-86164/Boat+Trailer+Bunk+Slick+Kit,+10+piece.html

 

[bjennings79]

Re: Replacing bunks. 2x6 or 2x4?

I only have 4 bunk supports over the entire 20 feet, so I guess thats almost 7 feet apart. Will definitely need to go with the 2x6 then. I found a pretty good price on stainless hardware at Mcfeelys website. Decided to go with regular hex head bolts, countersunk, with either a nylock or double nut on the underside.

It appears that MCA treated wood is safe for use with aluminum. They carry it under the brand "Yellawood" at several of the large lumber yards.