View Full Version : help on winch post for jetski trailer

Bob S2
08-07-2004, 10:07 AM
Looking for someone with experience with boat trailers and the like. I'm building a post that will clamp onto the tongue of a small utility trailer to help pull a jet ski up. This post will hold a small winch 16 inches above the tongue, which is 2x3. I've built the bracket and welded it onto a post. Now it's time to drill the holes for the bolts that will clamp it down on the trailer. The bolts are 1/2 stainless steel. The bracket is a little long, and hangs over the tongue about 1.5 inches, and is made from 3/16 plate steel, about 4 inches wide. I've got plenty of room for the holes, my question is how close to the tongue of the trailer should the bolts be? I initially thought that I'd give about an 1/8 inch clearance between the shaft of the bolt and the tongue of the trailer, to keep movement minimal in case it does shift at all. I just looked at a a front wheel for a boat trailer, and there was a lot room between the bolts and the tongue - around 1/2 to 3/4 of an inch. Any thought to this? I don't want to give a lot of room in case in the process of winching the jetski it shifts on the tongue, but on the other hand I don't want to be so close as to cause problems mounting it. Any thoughts or doesn't it matter? 3/16 thick x4 inches long is a lot of space - 2 bolts 1/2 thick with nyloc nuts should be enough, shouldn't it?

08-07-2004, 10:38 AM
When you say bolts, I presume you are talking u-bolts. The trailers I've dealt with used a smaller upright dimension than the tube they were clamping to, to provide with for the nut to fit on top, and still turn. If this isn't the case with yours, I would weld two small (3 x 1) tabs on the side of your plate so that it slips over the tounge on both sides, thus preventing any twisting or turning of the winch post. A guy could also use longer tabs on each side and bolt clear through the tongue of the trailer, but this would prevent easy, on site adjustment of the post. I do think however, that if it were my jet ski trailer I wouldn't be too worried about a jet ski providing enough resistance to move it around. Just my .02! Post a pic when you are done.

Bob S2
08-07-2004, 12:07 PM
Heres a picture of the post I'm making. That's not the trailer tongue, just some 2x3 I had.

08-07-2004, 12:56 PM
Bob, what you have described in your first post sounds fine, go with the 1/8 clearance. Should have no problem.

08-07-2004, 01:44 PM
If you bolt that straight through, it won't adjust very easy when you are at the lake, and need to winch on a different sled than yours.

Bob S2
08-07-2004, 03:34 PM
Sounds good. I'll go with about a 1/8 inch to 3/16ths clearance between the bolt and the tongue. That should allow for plenty of difference due to paint, any decals, slight variation in the metal, etc. I look forward to seeing how it looks finished! Just welded the bracket onto the upright. Tomorrow I'll cut the the top plate and weld it on. I had plenty of heat in the lower bracket due to all the cutting and grinding, etc. I may throw it on the grill to get some heat into it before welding tomorrow. What do you guys think? I'm thinking of wrapping it in foil to keep any grease from getting on it.

08-07-2004, 03:57 PM
Bob, this is how mine is made. I know this might not be what you are looking for, but it's just an alternative method.


08-07-2004, 11:35 PM

Boat trailer frames come in half inch increments and those winch mounts that people by after the fact are sort of generic 'fit-all' mounts. You will see some with some horrible sloppy fits. Sometimes you'll see 2 or 3 inches of extra flange sticking down with more holes unused. LOL!! :eek:

You are building yours to custom fit your trailer so make it as snug as you see fit. As mentioned tho, don't make it so tight you gouge up the paint is all.

Bob S2
08-09-2004, 08:34 AM
Drilled the holes for mounting the winch last night, and man I love cobalt drill bits! I thought of something though, about the proper way to drill larger holes. I started with a small drill bit, went to a larger bit, then the 1/4 drill bit, and finished up with my 3/8 drill bit. Is this the best way to do it, or should I have just tried to drill the hole once using the large drill bit? Drilling using multiple bits in steps seems slower but easier to drill. Does this wear out the bits' outside edges, and is this not a good way to work? I'm interested in learning the right way to do things, not just the easy way. Also, what safety precautions does everyone use? Small twisted metal shards come off the bit (running at lowest speed it's not too bad). Do you guys have a containment system similar to a drip tank for a bandsaw, or do you just let it collect under the drill press? I'm wearing safety goggles, but should probably have the full face protection, right?

The project is coming along nicely. Tonight I need to finish drilling the holes. Tomorrow I'll be welding on the top winch-mount plate, and then de-rusting the surface rust off all the metal. I'm thinking of just using some automotive brake cleaner, sinceit's just the light surface rust. I'm hoping to get the first coat of paint on it this week.

08-09-2004, 09:28 AM
Personally if I drill in multiple steps, I usually try to drill the pilot hole just large enough to accomodate the web thickness of the larger bit. This makes downfeed easy and reduces heat transfer into the bit while keeping the cutting lips fully engaged. If you go in really small increments (from 7/16 to 1/2 for instance) it puts a lot of stress on the outside edges of the lip which can lead to chipping of the bit, and the bit also tends to wander and not index in the hole as well.

08-09-2004, 09:43 AM
As mentioned above, when drilling large holes you should always drill a pilot hole. The larger drill bits aren't really designed to drill straight though steel. Too much heat transfer to the bit and it dulls the inner cutting edge. :)

08-13-2004, 12:23 AM
My oem trailer is made like that but uses a couple of pieces of L angle instead of the 2 by 3. It sucks but is usable since I cut and angled it so it would balance and line up right. You can do a far better job with that piece of 2 by 3 and a couple bolts to pinch it in place. A seadoo is light enough that you don't need much strength up front. I don't even use the winch with mine except to secure it tightly into the rubber "V" blocks the bow snuggles into. It is more of a locking mechanism than a winch in function anyways so the cheapest chinese winch is more than enough. The tongue on mine is thin .100 stuff which is plenty thick for a seadoo. Make that tongue nice and long so it doesn't jack knife all over when you are backing up. Mine is only 6' to the Y frame and it handles terribly. 8' would be lots better. Another nice touch is locating that ****ed huge license plate the states mandate in a place where it won't slice anyone. The way they all come from the factory the sharp edge is always sticking out waiting to shave someone's shins.