Modifying a trailer

[Skippy Liz]

I want to modify a pontoon trailer for my 25 ft O'Day, swing keel.

Any suggestion?

This seems easy, weld four posts to trailer to cradle boat, right?

Thanks

 

[txtowman]

not quite.

you need to know where to support the boat properly under the bulheads.

 

[MrUnix]

Get the bolt on posts and adjustable top pieces so you can adjust them properly. Remember, a motorboat has a center of gravity much further back than a sailboat. This can make fitting a problem as usually you need the front winch support further back than you would with a motor boat. If you can't relocate the winch support, another alternative is to move the axle(s) forward, if possible. Sometimes, you gotta do both, and having bolt-on parts is much easier than cutting and welding.

I've done a bunch of conversions (motorboat -> sailboat and visa versa), and the easiest way to get started is to get your boat up off the ground with clearance to slide the new trailer under. Center it about where you think it should be and then bolt on the supports/cradle and give it a test weigh.. Get out your bathroom scale and put it under the front of the trailer. It should be roughly 10-15% of the gross weight of your boat/trailer. I'm not familiar with the weight of an O'Day 25, but for example, say it's displacement (dry) is 2500 pounds. Add another 500 for the trailer and misc. storage. That setup should have about 300-350 pounds at the hitch. If you have too much weight up front, you need to slide things back.. if too little weight, slide forward. Once you have the boat balanced, crank down on the supports and decide what to do with the winch support.

One word of caution.. be careful when you first check hitch weight.. I once did a sailboat->motorboat conversion and had the thing pulled as far forward as I could (snugged up against the winch support/bow snubber) and thought I'd be OK... wrong! As soon as I released the trailer from the hitch, it went flying up in the air and drove the lower unit of the outboard about a foot and a half into the ground! I wound up having to cut off the winch support (no bolt on with this trailer!) and move it forward over 3 feet to get the boat balanced

Cheers,
Brad

PS: You might want to look at this homemade trailer design to get an idea of where to place your bunks and general measurements:

http://oday.sailboatowners.com/inde...id=257&cat_id=127&aid=6812&page=article&mn=25

 

[tommays]

A keel boat would use at least 6 and the KEEL

BUT most swing keels use bunks like a power boat for weight distribution without hull stress and support the swing keel but do NOT use it to support the boat

 

[dscribner]

Ignore the rust please. And the hull gets painted this spring.

I used arms from a heavy duty rack system. They are 4X4 steel tubes with channels that clip over the frame and u-bolts to secure them. Then I bolted the roller assemblies that were originally on the trailer to the stantions. I fabricated these up in a weekend from scrap in order to get her home. It works great, but presently looks awful. I'll replace them this spring with some proper stantions. Probably 3" channel so it can drain properly.

Keep in ind most of the advice you get will be from fixed keel sailors. This is a horse of another color. Your boat will probably be able to balance on the keel trunk, almost. I figure that each roller assembly takes 500 lbs static load, leaving 2000 lbs for the keel.

Good luck!

Don

 

[woodster]

a word of caution here ....make sure you have enough axel capaticy to handle the load ...if you only have a 1000 lb axel and your boat weighs 2500lbs you need more axel and springs...... the gross weight of trailer and boat and gear is your taget weight.....the axels come in sizes rangeing from 1000lbs and up if you have 3000 gross one axel that has a 3500lb rateing will do or two axels rateing 1500lbs each in tandom will be ok too...i prefer tandom axel trailers as opposed to single for ease of handling .....two 3500lb axels in tandom will be over kill for a 3000lb gross weight but 2 2000lb axel in tandom will be great for that 3000 gross weight and it makes handleing much safer and better...most people never take in consideration the total weight when doing theses mods and as a result over load the under carrage of the trailer .....hopes this helps...

regards

woody

 

[kpgraci]

One word of caution.. be careful when you first check hitch weight

Tongue wt s/b 9% to 14% gross wt. Actual front/rear position of boat will be trial and error.

 

[Barnacle Bill]

Most pontoon boat trailers that I have seen are very narrow so it fits between the two pontoons and hence it would be too narrow for the average sailboat.