To carriage bolt or not carriage bolt

[gonefishie]

I'm going to be replacing the bunks on my trailer this weekend. Right now the bunks are attached to the bracket by big sheet metal screws. The wood rotted where the screw goes into it so the bunks are loose. I don't like this set up because few years down the road I'm going to have the same issue again. I thought about drill out a hole on the top side of the new bunk, drop the carriage bolt in and tight it down with a nut on the bottom side. How can I do this so that the head of the bolt not making contact with the boat? Should I drop the bolt in first and then install the carpet which would cover the bolt hole opening or the carpet first then the bolt? My concern is that the hole would holds water and speeds up the rotting process. What do you guys think? Could the carriage bolt works itself loose inside the hole? Does it even works with wood?

 

[jaxnjil]

Re: To carriage bolt or not carriage bolt

well when i changed the buck boards on the trailer for our old bayliner i did as you said.
i drilled a 1" or so hole 1/4" deep for a counter sink, and then drilled 1/4" holes the rest of the way threw. i then used 5/16" carriage bolts and taped them in. idea being the smaller holes will grip the bolts and be less likely to strip out of the wood if tightening later. then warped with the carpet stuff the sell by the roll here on i-boats

i never thought of the counter sink holding water and causing a problem and haven't had to tighten the bolts again.
all i can tell you is it worked ok then and is still working now

 

[SS MAYFLOAT]

Re: To carriage bolt or not carriage bolt

Only problem I hate when using carriage bolts is when they have been in a long time. Usually then they have to be cut off as they tend to just strip out in the wood. Then having them recessed would make it even harder. Using stainless is a bit more expensive, but makes it a breeze to remove when needed.

Drill a small hole in the recess all the way through to drain the water, or just fill the void with silicone. Good Luck

 

[gonefishie]

Re: To carriage bolt or not carriage bolt

, or just fill the void with silicone. Good Luck

Duhh! why didn't I think of that? :redface: Thanks fellas! Off to Home depot now.

 

[jaxnjil]

Re: To carriage bolt or not carriage bolt

what are you using for lumber?
we used pressure treated 2x6's

ours had lag screws that striped and fell out. though about regular cap screws but didn't want to have hole in carpet to hold wrench

 

[Bondo]

Re: To carriage bolt or not carriage bolt

Ayuh,... Use P/T wood,+ 1, 1/4" x 3/8" Lag Bolts Up from below....

Can't Scracth the boat if the bolt can't reach it...
No holes to plug or trap water,... Self draining so to speak...

 

[Bass Man Bruce]

Re: To carriage bolt or not carriage bolt

Agree with above.
If later removal is questionable snug the carriage bolts in lace and then tighten with a jamb nut.

 

[gonefishie]

Re: To carriage bolt or not carriage bolt

what are you using for lumber?
we used pressure treated 2x6's

ours had lag screws that striped and fell out. though about regular cap screws but didn't want to have hole in carpet to hold wrench

I'm using 2x4 pressure treated to match the original bunk. My lag bolt fell off too, I launched the boat, went to park the trailer and noticed one of the bunk had seperated from the bracket. Got some galvanized 5/16 x 2" carriage bolts, cut washers, nuts and a 3/4" counter sink bit last night. I tested it out on a piece of 2x6, worked great.

 

[AZSenza]

Re: To carriage bolt or not carriage bolt

I did the carriage bolts on my last trailer, worked great. Monday I'm doing the same with my current trailer that i should have done last year!

 

[wajajaja02]

Re: To carriage bolt or not carriage bolt

I bolted mine and use pressure treated 2x4, and didnt carpet at all, I put the ez on teflon sliders on instead directly to the wood.

 

[fishrdan]

Re: To carriage bolt or not carriage bolt

I've used carriage bolts, cut washers and nuts before and had problems with them loosening and dropping the nuts. I guess road vibration and wood compression/shrinkage would loosen them up after a few years. I double nutted and locktite'd the carriage bolts, so that even if there was slop between the bracket and bunk, the nuts wouldn't loosen. Only other problem I've run into is the wood stripping out and not grabbing the carriage bolts after years in use.

On my new bunks I countersunk the holes with a 2" forstner bit, then used hex bolts and fender washers to alleviate the stripped wood / carriage bolt problem. Double nutted/locktite'd the bolts and haven't had any problems with loosing bunk hardware. I also drilled drain holes in the countersunk holes like SS suggested.

If not double nutting I'd use nylon lock nuts to keep the nuts on the bolt if/when the bunks start to loosen up.

 

[jaxnjil]

Re: To carriage bolt or not carriage bolt

I'm using 2x4 pressure treated to match the original bunk. My lag bolt fell off too, I launched the boat, went to park the trailer and noticed one of the bunk had seperated from the bracket. Got some galvanized 5/16 x 2" carriage bolts, cut washers, nuts and a 3/4" counter sink bit last night. I tested it out on a piece of 2x6, worked great.

that's pretty much how we did ours. on thing i didn't mention was i got carriage bolts about 3/4" longer that need in the event they did loosen and couldn't tighten i could always grip the threads sticking out below the nuts with vice grips an still tighten

 

[redone4x4]

Re: To carriage bolt or not carriage bolt

that's pretty much how we did ours. on thing i didn't mention was i got carriage bolts about 3/4" longer that need in the event they did loosen and couldn't tighten i could always grip the threads sticking out below the nuts with vice grips an still tighten

I did the same, left them hanging down long. had to tighten them after the first few trips out, but they seem solid now. I used lockwashers on mine also.

 

[Gary H NC]

Re: To carriage bolt or not carriage bolt

Stainless carriage bolts on mine too.Nylon locking nuts and have never had a problem.Then i put the Surfix bunk glides over the carpet.I can push the boat off with one hand..

 

[skargo]

Re: To carriage bolt or not carriage bolt

I actually used lag bolts. I drilled pilot holes, filled them with 5200 and tightened them. So far so good.

 

[reelfishin]

Re: To carriage bolt or not carriage bolt

I used plain 3/8" carriage bolts on mine with nylock nuts, then filled the countersunk hole with 5200, figuring that it would keep water out and help prevent the bolt from every spinning. I didn't worry about using stainless bolts figuring that by the time the bunk boards are due for replacement, the bolts and brackets will probably also be due for replacement. PT lumber attacks the metal as well. I got away from using SS bolts on the trailer anywhere I need strength after having several bunk bracket bolts shear or snap under load.
The same goes for galvanized bolts, most are too soft and break easily. I did paint the bolts before use to slow the inevitable corrosion. It's also a freshwater trailer to I doubt I'll have any issues with corrosion anyhow anytime soon. The original bunks, bolts, and brackets lasted over 28 years.

 

[jonsquatch]

Re: To carriage bolt or not carriage bolt

On the Escort trailer I had on my old 88 Bayliner I had to borrow a battery operated sawzall to cut off 2 of the old carriage bolts as the nuts were good and stuck and the bolt was spinning and there was nothing to grab it with. It had an enclosed area around the nut, the only thing I could turn them with was one of those ratcheting gear wrenches. I couldn't use lag bolts and didn't want holes in the new carpet so I just countersunk my new holes and made the through hole a bit snug and then drove the bolt almost all the way in and filled the counter sink with 5 minute self mixing epoxy. I used some waxed washers and the nuts to snug them the rest of the way and let one side cure while I did the other, then put the carpet on the cured one and rinse and repeat. I didn't have any trouble backing the nuts and prying the washers off. If they still spin down the road then at least I did everything I could think of to stop it.