Trailer Repair - Help

[derrek]

I have an EZ Loader bunk trailer for my 18' Lund. The wood screws securing the trailer to the front of my bunks have become loose, or fallen out. I've managed a quick-fix, but need to move my bunks back slightly to properly install new screws. I was told that rather than using screws in the underside of the bunks, counter-sink carriage bolts through the top of the bunks, and cover them with whatever matting I use. The idea makes sense from a strength standpoint, but is my boat at risk by having these bolts installed from the top? I've followed this board for some time, and you guys always provide great advice. What is my best option?

[FJH1]

Make sure to countersink the heads into the bunk board, if you don't you will risk damage.

Best Regards,

FJH

[RANGER]

Yep! That's the way to go - counter sinking carriage bolts. Counter sink drill bits are not expensive and you can get each hole nearly perfectly uniform in depth by wrapping masking tape around the bit shaft at the desired depth and STOPPING the drill when the wood touches the tape. When the counter sinking is done your installed bolt head should be 3/16ths to 1/4 inch below the board surface.

My suggestion - use stainless steel bolts, washers and Ny-lock nuts. When you torque the bolts be sure you torque them so that the square nuckle under the cap is buried into the bunk. To manage this, when you place the bolt in the countersunk hole you have drilled place a drift pin, center punch or a rachet wrench extension piece on the head and wack it until you hear a definite change in pitch coming from the board. Then install your washer and nut. This set up will out last your wood bunks.


RANGER


"KEEP YOUR LINES WET, YOUR POWDER DRY and THE BEER COLD!"

[GregK]

Just finished replacing the carpet on the bunks for my Ranger. It comes from the factory with counter sunk carriage bolts. You can't go wrong. Just make sure the head is buried about 1/4 inch and there is no way it will get to the boat. I would also recommend stainless if you can find it.

[AquaMan]

Although the carriage bolts will work, I would go with stainless steel course thread 3/8" bolts and teflon insert lock nuts. Drill your holes and use a spade bit to countersink a hole large enough to accept a 3/8" stainless washer and 1/4" deep. Use a washer on the nut side and tighten till secure. Do not crush the wood, this will create weeknesses and rot in years to come.

A carriage bolt and lock washer will only be stong if you crush the wood to keep the lock washer tight. Over time a carriage bolt with a lock washer will come loose due to expanding and shinking wood. The lock washer only works when the nut is tight, where as the teflon nut always stays tight.

Just a thought as long as you are replaceing them all.

AquaMan~~~~~~~~~~~~~

.·´¯° --- "It all begins and ends at the water's edge"

Eric@crowncomputerinc.com

[derrek]

Thanks for your help, gentlemen. This is the best board around.

[Gord]

carriage bolts are not designed to be countersunk. look under the head of the bolt and you will see a square stepped shoulder. that shoulder bites down into the wood and holds the head of the bolt to prevent it from spinning when the nut is tightened. tightening the nut should be enough to pull the round head of the carriage bolt down into the board. be sure to put a big flat washer on the bolt before the nut goes on. use locktight and a self locking nut. use a thicker bolt so that it won't break when torqued. try this on a test piece just to prove to yourself it works. If you countersink the bolt, it will just spin in the hole. whew.... i need a beer after that, my typing finger needs a rest.

[Gord]

OOPS.... forgot to mention, be sure to drill the bolt holes the same size as the carriage bolts. When the hole is the same size you will have to push the bolt into the hole. It will be a tight fit. If it starts out as a tight fit it will stay that way. A little wood preservative in the hole would also be a good idea.