trailer build for 25.5 fin keel

Oct 1, 2017
4
hunter 25.5 lake norman
I was given a 1985 Hunter 25.5 last june. I'm a contractor. a few months prior i had done some work for a guy who lived on lake norman, a lake just north of charlotte nc. i notice the boat docked at his neighbors house, and could tell it had not been used in awhile. i asked the homeowner about it. he agreed that it looked neglected, but knew nothing else.

i finished the project in april, and thought nothing more of the boat. a few months later the homeowner texts me saying his neighbor is selling the boat and the price is zero. i had never met the neighbor. a few weeks later we met up and he signed over the title.

I wanted to get it to my house, where I could begin to restore it.

my plan was to store it at a friends dock until i could get a trailer for it. i figured how hard could that be?

turned out to be pretty hard. its the fin keel version, that drafts 4' 6". hunter also offered a shoal draft keel version in that same model. that would have been much easier.

i searched all over for a fin keel sailboat trailer. they are hard to come by. i guess most fin keelers dont have trailers? suppose they just haul out periodically?

after months of searching i gave up.

my new plan was to build a trailer. the trailer build didnt seem to complicated. i've done some welding. but figuring where to place the uprights, and at what height was a different story. even though my uprights would be adjustable in height to some degree, my fear was that they'd be off, and have to be cut and redone.

i finally settled on buying a used trailer and modifing it. this made me feel a little more optimistic about the outcome, but did nothing to solve my upright placement issue. i thought maybe if i could get a lines plan for the hull, i might be able to use it to loft full scale templates of hull sections.

but i abandoned this idea too, and my project evolved again.

now i was settled. i was going to start with a used trailer and build a wood frame on it, that i could then be build wood uprigths from. this would allow me to have the boat hoisted out, set on the trailer, then build the wood uprights to the hull. once completed, the hoist straps would be taken away, and i'd drive off. i'd later weld metal uprights one by one as i removed the wood uprights.

soo. to my knowledge, theres is no other trailerable load comparable to a fin keel sailboat. it bears most its weight on a single point. its like towing a 6000lb, 25 foot long, 9 foot wide irregularly shaped spinning top. its spooky just to look at, scary to tow, and terrifying to design. I was haunted by visions of it laying in the street.

i had to figure where to place the axles, and where to place the "keel cradle". weight distribution would be critical with it almost all bearing on a single point. technically, it should be 80% on the keel, with uprights only taking 20%.

another think complicating my trailer build was that theres only one travel lift on lake norman. they're always booked, and not crazy about their lift sitting idle. this forced me to do as much preliminary work as possible.

so the trailer is 21' x 6'. i printed the spec sheet on the hunter model, and used it to make a scaled version of my trailer, that I drew on a small piece of paper and then superimposed it over the hunter spec sheet, to figure where to place my axles and the keel cradle. i wanted the keel to sit directly over the axles.

after getting my axles moved, i then welded two 1/4" x 6" flat stock pieces directy to the frame, spaning three cross members. it was 54" long. i then drilled six holes in the two pieces and bolted treated 2 x 6s to them.

i drilled several holes in the top portion of the longitudinals of the trailer frame and bolted a 2" x 4" flat to it. i used it like a sill plate to build a 2" x 6" frame from. similar to building a deck.

i replaced the coupler and lights, and then scheduled the big lift.

it was lifted out and set on the keel cradle. the lift operator leveled it and left it to me. i used scrap wood to "deck" a few areas where i need my uprights to go or their braces. i used treated 2" x 4" for uprights and bracing, and pads i had made earlier.

the pads were made from 3/4" treated plywood with pieces of rubber door mat glued to it. the porous texture of the door mat top adhered perfectly with adhesive and the bottom of the door mat held fast to the hull. on the bottom side of the pad, i fastened two strips of scrap wood spaced just wider than a 2 x 4.

it worked well. I made it the 18 miles from the marina to my house and the boat is still standing now.

hopes this helps someone.
 

Attachments

Jun 8, 2004
10,400
-na -NA Anywhere USA
Looks like all seasons marine. I know the lift operator. Sounds like Graham sold the boat originally as the s dealer.

What is the designed or max load on the trailer or GVW? What is the load range for the each tire. What is the tire.
 
Oct 1, 2017
4
hunter 25.5 lake norman
yes it was all seasons. didn't meet a graham, but did meet tim and joanne.

I dropped your name. tim sends his best.

good eye dave. the axles and tires are undersized. I cant plead ignorance either. I was going to include this in the original post, but it was already too long.

when considering replacing the axle bearings, I called to price them. person I spoke to believed they were from a 2200lb axle, but she wasn't certain. I knew that by the axle diameter and lug pattern that it could also be a 3500lb. I went with this assumption, and figured I had a 7k capacity.

I also figured that worst case, they were 2200, making my capacity 4400, but figured with a 4500lb boat weight plus the trailer weight, I'd be around 6000. I was OK with this. I worry less about overloading a tandem axle. I wouldn't do it with a single axle.

what I didn't plan on was the boat weighing 6000lbs. I guess the extra weight came from gear, which wasn't much, and osmotic water intrusion. the bottom is covering with blisters.

so know I'm at approximately 7500, which was not cool. I didn't realize how bad it was until I got on the road. it was awful. I couldn't go over 30. anything faster than that, and it would start snaking violently.

so if that wasn't bad enough, the weight distribution is to far aft, also. again I didn't realize this till later, when I went to decouple at home. fortunately, I left the safety chains hooked up when I did this, because the front of the trailer rose. not gently either. the chains stopped the trailer back from bottoming out completely. it has negative tongue weight. I have to jack the back of the trailer to get the front to lower on my ball.

I haven't towed it since. my goal was to get it to my house and I achieved that goal.

if I did it again I would decouple to do the build. this way would know if the weight was right. I was hooked to the trailer the whole time.

tires are 13". load range c. 1360lb per, I think. it was the highest load range I could get. I replaced two and the other two were good. having 4 good tires made feel a little better about being overweight, also.

in hindsight, the tire size should have been a dead giveaway. but in my defense, I have a cargo trailer with a single 3500 axle. I know cause I replaced it. it runs 15" tires, and has the same lug pattern as the sailboat trailer.

so, my plan is to add a third axle aft. I think this will solve my weight distribution problem, and my overweight issue. that would give me 6600lb if go with another 2200 axle, or if available a 3500lb one. adding a 3500 lb axle would give me a 7900lb capacity, and a ton of piece of mind.
 
Oct 1, 2017
4
hunter 25.5 lake norman
whats an s dealer?

dave I have plans to restore this boat. the bottom gelcoat has to come off, needs paint or epoxy all over. the main bulkhead has water damage at the chainplates, and likely under the cabin sole. I haven't yet removed it. rest of the interior is good, cushions need recovering. I also plan to modify the cockpit. removing some of the bench seating, and adding a helm. going to beef up cockpit sole too. it crunches under foot. the deck is sound, but the pop top is delaminating. I was thinking of deleting altogether. making a fixed trunk extension. like 6". that would give 6 foot of clearance.

i'm pretty ambitious, and not afraid of big projects, but would like your opinion as a former dealer.

is this boat worthy of all this?
 
Oct 24, 2010
2,405
Hunter 30 Everett, WA
The trailer sway problem is likely to be simply loading. Trailers need to be front loaded. With a single axle at least 10% of the weight needs to be on the hitch. With multiple axles I don't know how to calculate loading but I know it still must be forward.

Ken
 
Jun 8, 2004
10,400
-na -NA Anywhere USA
Ken.

Trailer is an issue that needs to be addressed. May have a lead for a trailer used of course. However it depends on the condition of the boat before going any further.
Chad. Send me a private messsage with phone. Advise lake Norman. Tim did represent hunter for me at one point. Tim is a good man to know
Dave
 
Oct 3, 2006
1,023
Hunter 29.5 Toms River
I think your best bet is going to be to build a steel cradle. Getting the boat transferred at home is going to be a job... but once it is secured in a cradle, it can be transported via a properly rated flat trailer, and also dropped anywhere at a boatyard by the travel lift.

upload_2018-4-9_9-8-23.png
 
Jun 8, 2004
10,400
-na -NA Anywhere USA
Depends on this trailer to be used. Have yet to hear from the owner and if so will advise on discussion. One other thing that also no one brought up is the forward portion of that trailer could collapse if over loaded and that too is scary. I have seen the aftermath as well as in person. I was pulling a 33 foot keel sailboat on my trailer following behind another boat 36 footer on a professional driver’s trailer when that trailer collapsed. Due to professional experience of that driver, no injury or other vehicles involved. I have designed trailers too
 
Nov 26, 2012
1,654
C&C 40-2 Berkeley
Honestly, looking at the photos, I think you got lucky. I would not trust that structure to go bouncing down the road with that much weight on it for any distance at all. It should be steel and, really, the weight is not supposed to be a point load. A "real" trailer is designed so that you can float the boat onto it. In other words, the keel does not touch at the bottom.
 
Jun 8, 2004
10,400
-na -NA Anywhere USA
Hate to say but weight is a major issue in trailer design and the keel tray is designed to carry the load with other fixed stands/bunk boards to support the boat upright. In addition most trailers are designed for launching but there are a few only for transport. It depends on what you want to do with a trailer first. Then designing from there
 

JRT

.
Feb 14, 2017
2,054
Catalina 310 211 Lake Guntersville, AL
Well is it worth it? I don't know this Hunter 25.5 has a ton of money in it and it sold from a SBO owner to this person and now he is selling it.

http://sailingtexas.com/201701/shunter255137n.html

I think a normal Hunter 25.5 is a $4-8k boat. So since it was free you have $4-8k to spend to catch up:)

Read up on the 'blister repair' a bit. No experience but I've read and have been told too many people get far to aggressive in removing them and go too far into the hull.