The bottom of my boat currently sits 4.5" above the top of trailer frame, and I would like to lower the boat if possible. Does 4.5" seem a little high to you guys? I'm thinking of buying "Ultimate Bunk Boards", lying them flat, and bolting right to trailer frame(countersinking bolt heads) Is that a bad idea? Are bunk brackets absolutely necessary? Thanks.

Well if you have a completely flat bottom boat, it might be okay. If it's got a v to it at all, its going to hit the frame when you load it.

One other thing to consider.  Lower the boat by 4.5 inches, and decrease the clearance between the road and the motor skeg by 4.5 inches.

Thanks. My boat is a flat bottom jon. The motor is no problem because I don't have an outboard, electric only.

If I do this, I think I will lay a 2X4 under the Ultimate bunks for extra strength, and to eliminate any possible flexing.

So is the 4.5" between bottom of boat and top of trailer frame about normal?

If I bolt a 2X4 to my galvanized trailer, is it OK to use treated wood?

Jon boat...no motor...you'll be fine. Treated wood will be fine.

Thanks. So the treated lumber is only bad with aluminum, NOT my galvanized trailer?

The copper in today's treated lumber will not get along with your aluminum jon boat.  Big no no today!  Use regular lumber or do like I did and put plastic bunk slicks or something to separate the boat from the lumber.  Carpet will not stop the corrosion problem.

Everything I've looked into about mixing wood with aluminum suggests untreated lumber. 

I'm not asking about mixing treated lumber and aluminum. I asked if it's OK to bolt a treated 2X4 to my galvanized trailer.

I'm not asking about mixing treated lumber and aluminum. I asked if it's OK to bolt a treated 2X4 to my galvanized trailer.

 

 

Oh. My mistake. You can go ahead and do whatever you want to pal. No need to be a jerk.

I'm not asking about mixing treated lumber and aluminum. I asked if it's OK to bolt a treated 2X4 to my galvanized trailer.

your fine bolting it onto a galvanized trailer. However it wont do you any good it it eats through the boat thats sitting on top of it

your fine bolting it onto a galvanized trailer. However it wont do you any good it it eats through the boat thats sitting on top of it

 

Thanks. The treated 2X4 wouldn't touch the boat. On top of it would be the plastic Ultimate bunk board.