Setting bunks

[El Matador]

I recently bought an aluminum boat and the trailer was in pretty bad shape. It's been sanded but not repainted. The "bunks" are two, two-foot 2x4s underneath the hull. I would like to add some to the side of the boat for a little extra support. I just don't know the best way to do that. I was thinking using square tubing welding to the trailer, plate on the sides to support the tubing, and carpet coated 2x4s as the bunks. Is there a proper way to align the bunks? Also is there a better way to secure them to the trailer? Thanks.

-Chris

 

[Dunaruna]

Re: Setting bunks

Just finished rebuilding this one. The new bunks are 4x2 treated pine with poly skids. The skids are screwed and glued (SS screws), the pine is bolted to the brackets with gal bolts. The mounting brackets are available from most trailer supply shops, they can be bolted or welded onto the frame. I prefer bolted, that way they can be adjusted for fine tuning in the future.

 

[tashasdaddy]

Re: Setting bunks

the only difference that i do, is i use full 8 foot 2x's and connect to all 3 cross members, and let the excess hand of the rear. this gives you more opportunity to move the boat forward or back to adjust tongue weight, or to use trailer for a longer boat. there are many types of the side guide ons. i also like to load the boat, then adjust the bunks to fit the boat. you can either use a jack under the trailer to adjust, or take a 2 x4 and use the trailer frame, as a fulcrum, to adjust the bunks, then tighten all bolts.


http://www.iboats.com/Boat_Trailer_...ategory--**********.484527972--view_id.238441

 

[Fingernip]

Re: Setting bunks

Not to hijack or anything.... but tashasdaddy, how far would you say is safe to let the bunk overhang past the rear of the trailer? I need to extend mine quite a bit but im worried about there being no support under the bunk. Also is there any reason to lay the boards down flat over standing them on end? My trailer has the boards laying down and i can see them taking on the slight contour of the hull.

 

[tashasdaddy]

Re: Setting bunks

lying down the have about 1/4 of the strength of standing up. i have seen where people made a T out of 2 boards bottom upright, top piece flat. in contruction this is called a stiff back. i entended upright as much as 18 inches, past the last mount.

 

[Fingernip]

Re: Setting bunks

I like the stiffback idea as i have a fairly heavy 21' boat and no keel rollers on my trailer to take some of the weight. I may have to try that... ill likely be moving my winch stand up though as its sitting without an engine/outdrive now so i cant possibly balance it as is. It seems to be lighter than I would expect at the tongue considering its 600+lbs light at the stern right now. I cant really lift it by hand but i would estimate it to be 400lbs on a 3000lb (waterlogged) boat + 1000lb trailer.

 

[El Matador]

Re: Setting bunks

Thanks everybody for your advice and tips. As soon as I save up a little money I'll start the project and be sure to take pictures of it so you can critique it. Again I appriciate your help.

-Chris

 

[El Matador]

Re: Setting bunks

I'd also like to add bunks so that they sit up on the side of the boat a little above the water line to help cradle it when a tow it. I can't really find any mounting brackets that would work. I was going to fabricate a mounting bracket. Inside the bracket I want to weld 1/8"x1 1/4" square tubing so I can insert 1/8" x 1" square tubing attached to the bunks. Drilling holes would make it adjustable. Anybody have a better way or know of premade brackets similar to what I'm looking for?

-Chris

 

[Seon]

Re: Setting bunks

I've read that using composite boards from Lowes or Home Depot, the carpet covering the boards are not needed because once wet, the boat will slide right on.
At any rate, I just ordered a Disc brake kit to overhaul my 21' trailer and will be using the composite boards.

 

[El Matador]

Re: Setting bunks

Alright well it'll probobly be a few weeks before I get everything for the trailer. I'm gonna order everything at once and try to get it done quick so I can repaint and not fight rusting. Let me know how those composite boards work out if you get them on soon.

 

[tashasdaddy]

Re: Setting bunks

for bottom bunk, the composite will not work, they don't not have the rigidity, of regular lumber.

 

[El Matador]

Re: Setting bunks

i've decided to go with pressure treated pine. Should I put a water sealant on the boards before I put the carpet on them?

 

[tashasdaddy]

Re: Setting bunks

no need.

 

[Seon]

Re: Setting bunks

for bottom bunk, the composite will not work, they don't not have the rigidity, of regular lumber.

I stopped at Home Depot where I learned that they can special order 2" thick Trex composition boards. They said that it's as strong as regular lumber and will work fine for bunks.