I'm changing the bunks on a used trailer I bought and need some
advice. The bunks are adjustable and I have measured the position on
my old trailer and have all the supports close. The only question is:

What's the best method to curve the bunks to fit the hull? The bunks
curve up in front and that is not too hard but they also curve inward
toward the center. The bunks are very stiff in that direction.

I'm using 2x6 wet fir ( not kiln dried)

Do I get the wood wet? Use a chain to pull them into position?
Something else?

I'd like to get the shape pretty close before I try loading the boat.

18ft I/O Wellcraft w/ Cobra outdrive. Single axile trailer.

Thanks

Kip

On Jun 18, 7:02*pm, kipmc4 wrote:
I'm changing the bunks on a used trailer I bought and need some
advice. The bunks are adjustable and I have measured the position on
my old trailer and have all the supports close. The only question is:

What's the best method to curve the bunks to fit the hull? The bunks
curve up in front and that is not too hard but they also curve inward
toward the center. The bunks are very stiff in that direction.

I'm using 2x6 wet fir ( not kiln dried)

Do I get the wood wet? *Use a chain to pull them into position?
Something else?

I'd like to get the shape pretty close before I try loading the boat.

18ft I/O Wellcraft w/ Cobra outdrive. Single axile trailer.

Thanks

Kip


I am no expert on this but I would suspect that it should happen
naturally over time once the bunks are properly positioned/adjusted on
the trailer to provide good support of the boat.

On Wed, 18 Jun 2008 16:02:12 -0700 (PDT), kipmc4 wrote:

I'm changing the bunks on a used trailer I bought and need some
advice. The bunks are adjustable and I have measured the position on
my old trailer and have all the supports close. The only question is:

What's the best method to curve the bunks to fit the hull? The bunks
curve up in front and that is not too hard but they also curve inward
toward the center. The bunks are very stiff in that direction.

I'm using 2x6 wet fir ( not kiln dried)

Do I get the wood wet? Use a chain to pull them into position?
Something else?

I'd like to get the shape pretty close before I try loading the boat.

18ft I/O Wellcraft w/ Cobra outdrive. Single axile trailer.

Thanks

Kip

I've got an 18' Key West on a trailer with bunks. The bunks do not appear
to have any curvature, other than that caused by the weight of the boat.
The brackets holding the bunks have three holes for adjustment. The front
bracket has the bunk in the highest position, the rear in the middle
position. The difference in height is about 2". There is no angling of the
bunks towards the centerline of the boat.

If pictures would be helpful, let me know and I'll take some. It would have
to be tomorrow at the earliest.
--
John *H*

kipmc4 wrote:
I'm changing the bunks on a used trailer I bought and need some
advice. The bunks are adjustable and I have measured the position on
my old trailer and have all the supports close. The only question is:

What's the best method to curve the bunks to fit the hull? The bunks
curve up in front and that is not too hard but they also curve inward
toward the center. The bunks are very stiff in that direction.

I'm using 2x6 wet fir ( not kiln dried)

Do I get the wood wet? Use a chain to pull them into position?
Something else?

I'd like to get the shape pretty close before I try loading the boat.

18ft I/O Wellcraft w/ Cobra outdrive. Single axile trailer.

Thanks

Kip

How long are the bunks? They should only be about five to six feet, or
so, on an 18' boat. The hull should be pretty flat and even in that
area. Just make sure the angle is right.

Also make sure they support the transom. I've seen boats with the bunks
mounted a full foot ahead of the transom. They should be flush.

On Jun 18, 5:27*pm, DK wrote:
kipmc4 wrote:
I'm changing the bunks on a used trailer I bought and need some
advice. The bunks are adjustable and I have measured the position on
my old trailer and have all the supports close. The only question is:

What's the best method to curve the bunks to fit the hull? The bunks
curve up in front and that is not too hard but they also curve inward
toward the center. The bunks are very stiff in that direction.

I'm using 2x6 wet fir ( not kiln dried)

Do I get the wood wet? *Use a chain to pull them into position?
Something else?

I'd like to get the shape pretty close before I try loading the boat.

18ft I/O Wellcraft w/ Cobra outdrive. Single axile trailer.

Thanks

Kip

How long are the bunks? *They should only be about five to six feet, or
so, on an 18' boat. *The hull should be pretty flat and even in that
area. *Just make sure the angle is right.

Also make sure they support the transom. *I've seen boats with the bunks
mounted a full foot ahead of the transom. *They should be flush.- Hide quoted text -

- Show quoted text -

****************************

Thanks to everyone who replied.

I do expect that the bunks will gradually take more of a curve as time
goes on but I don't want to damage the hull in the mean time.

Do you think that 2x6 is the way to go?

The current trailer, which fits the boat quite well, has bunks from
the transom about 9 ft 6 in ft forward to the 4th cross beam. The 4th
cross beam on the new (used) trailer is at 11 ft !!! I was going to
extent the bunks that far. Is that too far? Is there a drawback to
extending too far? The hull is more curved there so it takes more work
to get it to fit.

The 3rd cross beam is at 7 ft 4 inches. Do you think that that is far
enough forward? I could let the bunks extend past the support. The 2 x
6's will take a pretty good load even unsuported. .

Also this trailer has higher cross beams so I will have to go higher
to clear them which means having to back further into the water to
float it

It's a 4.3 L V6 I/O

Any more advice?

Kip

"kipmc4" wrote in message
...
On Jun 18, 5:27 pm, DK wrote:
kipmc4 wrote:
I'm changing the bunks on a used trailer I bought and need some
advice. The bunks are adjustable and I have measured the position on
my old trailer and have all the supports close. The only question is:

What's the best method to curve the bunks to fit the hull? The bunks
curve up in front and that is not too hard but they also curve inward
toward the center. The bunks are very stiff in that direction.

I'm using 2x6 wet fir ( not kiln dried)

Do I get the wood wet? Use a chain to pull them into position?
Something else?

I'd like to get the shape pretty close before I try loading the boat.

18ft I/O Wellcraft w/ Cobra outdrive. Single axile trailer.

Thanks

Kip

How long are the bunks? They should only be about five to six feet, or
so, on an 18' boat. The hull should be pretty flat and even in that
area. Just make sure the angle is right.

Also make sure they support the transom. I've seen boats with the bunks
mounted a full foot ahead of the transom. They should be flush.- Hide
quoted text -

- Show quoted text -

****************************

Thanks to everyone who replied.

I do expect that the bunks will gradually take more of a curve as time
goes on but I don't want to damage the hull in the mean time.

Do you think that 2x6 is the way to go?

The current trailer, which fits the boat quite well, has bunks from
the transom about 9 ft 6 in ft forward to the 4th cross beam. The 4th
cross beam on the new (used) trailer is at 11 ft !!! I was going to
extent the bunks that far. Is that too far? Is there a drawback to
extending too far? The hull is more curved there so it takes more work
to get it to fit.

The 3rd cross beam is at 7 ft 4 inches. Do you think that that is far
enough forward? I could let the bunks extend past the support. The 2 x
6's will take a pretty good load even unsuported. .

Also this trailer has higher cross beams so I will have to go higher
to clear them which means having to back further into the water to
float it

It's a 4.3 L V6 I/O

Any more advice?

Kip

Wonder if anyone in your area would have a steam box meant for making wood
pliable and bendable.

kipmc4 wrote:
On Jun 18, 5:27 pm, DK wrote:
kipmc4 wrote:
I'm changing the bunks on a used trailer I bought and need some
advice. The bunks are adjustable and I have measured the position on
my old trailer and have all the supports close. The only question is:
What's the best method to curve the bunks to fit the hull? The bunks
curve up in front and that is not too hard but they also curve inward
toward the center. The bunks are very stiff in that direction.
I'm using 2x6 wet fir ( not kiln dried)
Do I get the wood wet? Use a chain to pull them into position?
Something else?
I'd like to get the shape pretty close before I try loading the boat.
18ft I/O Wellcraft w/ Cobra outdrive. Single axile trailer.
Thanks
Kip
How long are the bunks? They should only be about five to six feet, or
so, on an 18' boat. The hull should be pretty flat and even in that
area. Just make sure the angle is right.

Also make sure they support the transom. I've seen boats with the bunks
mounted a full foot ahead of the transom. They should be flush.- Hide quoted text -

- Show quoted text -

****************************

Thanks to everyone who replied.

I do expect that the bunks will gradually take more of a curve as time
goes on but I don't want to damage the hull in the mean time.

Do you think that 2x6 is the way to go?

The current trailer, which fits the boat quite well, has bunks from
the transom about 9 ft 6 in ft forward to the 4th cross beam. The 4th
cross beam on the new (used) trailer is at 11 ft !!! I was going to
extent the bunks that far. Is that too far? Is there a drawback to
extending too far? The hull is more curved there so it takes more work
to get it to fit.

The 3rd cross beam is at 7 ft 4 inches. Do you think that that is far
enough forward? I could let the bunks extend past the support. The 2 x
6's will take a pretty good load even unsuported. .

Also this trailer has higher cross beams so I will have to go higher
to clear them which means having to back further into the water to
float it

It's a 4.3 L V6 I/O

Any more advice?

Kip


The weight of the boat is mostly in the aft 1/3'rd. Have you ever seen
the marina forklifts splash a boat? They can launch very large boats
with relatively short forks. You will need more support than that for
trailering but I can't imagine the need for 11' bunks on an 18' boat.
It's also not an exceptionally heavy boat and the bunks can cantilever a
foot, or so, in either direction from the brackets so I would suggest an
8' maximum if the hull and transom will still rest on the bunks.

As for the material, since the beams are higher, go with a 3X6 (they are
available) or 4X6 (they are probably cheaper than a 3X6) if you are
concerned about supporting the weight. A 2X8 will only make it that
more difficult to launch.

I would look around at several boat/trailer combos first and decide what
configuration you like.

On Wed, 18 Jun 2008 19:46:40 -0400, John H.
wrote:

On Wed, 18 Jun 2008 16:02:12 -0700 (PDT), kipmc4 wrote:

I'm changing the bunks on a used trailer I bought and need some
advice. The bunks are adjustable and I have measured the position on
my old trailer and have all the supports close. The only question is:

What's the best method to curve the bunks to fit the hull? The bunks
curve up in front and that is not too hard but they also curve inward
toward the center. The bunks are very stiff in that direction.

I'm using 2x6 wet fir ( not kiln dried)

Do I get the wood wet? Use a chain to pull them into position?
Something else?

I'd like to get the shape pretty close before I try loading the boat.

18ft I/O Wellcraft w/ Cobra outdrive. Single axile trailer.

Thanks

Kip

I've got an 18' Key West on a trailer with bunks. The bunks do not appear
to have any curvature, other than that caused by the weight of the boat.
The brackets holding the bunks have three holes for adjustment. The front
bracket has the bunk in the highest position, the rear in the middle
position. The difference in height is about 2". There is no angling of the
bunks towards the centerline of the boat.

If pictures would be helpful, let me know and I'll take some. It would have
to be tomorrow at the earliest.

Also, my bunks are 9 feet long, with 6 feet between the brackets.

Too late for pictures, won't be back until Monday evening. If you want
them, give me a shout.
--
John *H*

On Wed, 18 Jun 2008 16:02:12 -0700 (PDT), kipmc4 wrote:

I'm changing the bunks on a used trailer I bought and need some
advice. The bunks are adjustable and I have measured the position on
my old trailer and have all the supports close. The only question is:

What's the best method to curve the bunks to fit the hull? The bunks
curve up in front and that is not too hard but they also curve inward
toward the center. The bunks are very stiff in that direction.

I'm using 2x6 wet fir ( not kiln dried)

Do I get the wood wet? Use a chain to pull them into position?
Something else?

I'd like to get the shape pretty close before I try loading the boat.

18ft I/O Wellcraft w/ Cobra outdrive. Single axile trailer.

Thanks

Kip


Before you get buried in the nonsense you'll hear here in rec.boats...

There's no reason to curve the rear trailer bunks in towards the center
of the trailer.

Both bunks should be straight, on edge (perpendicular to the ground),
and, hopefully, beveled on the top inside edge where the wood meets the
deadrise of the boat's bottom. You want to move the bunks in or out on
the horizonal plane so they best support the weight of the boat.

The rear bunks on my trailer are either 2x10 or 2x12 on edge, cypress,
and carpeted with a slippery outdoor-rug-like fabric. I think they are
2x10, but I just don't recall. The trailer has front bunks, too. These
are not upright on edge, but are tilted on their sides to more closely
match the sharper "deadrise" of the boat's bottom towards the bow. As
these bunks go forward, they have been adjusted to move a bit closer to
the center of the trailer.

The rear bunks of the trailer should extend to the end of the bottom of
the boat at the transom, or close to it, within a couple of inches at least.

Here are some photos I took a while ago:

http://i21.photobucket.com/albums/b2...loadmaster.jpg

http://i21.photobucket.com/albums/b2...C/IMG_0444.jpg

http://i21.photobucket.com/albums/b2...C/IMG_0441.jpg

http://i21.photobucket.com/albums/b2...C/bowshot1.jpg

On Jun 18, 7:02*pm, kipmc4 wrote:
I'm changing the bunks on a used trailer I bought and need some
advice. The bunks are adjustable and I have measured the position on
my old trailer and have all the supports close. The only question is:

What's the best method to curve the bunks to fit the hull? The bunks
curve up in front and that is not too hard but they also curve inward
toward the center. The bunks are very stiff in that direction.

I'm using 2x6 wet fir ( not kiln dried)

Do I get the wood wet? *Use a chain to pull them into position?
Something else?

I'd like to get the shape pretty close before I try loading the boat.

18ft I/O Wellcraft w/ Cobra outdrive. Single axile trailer.

Thanks

Kip

Couple of pressure treated 2x6's covered with bunk material is all you
need. For that boat 10 ft will be fine. 6" side against the hull.
Just install them parallel. Ideally you want to position them so that
they are somewhat under the two main stringers that your engine mounts
sit on. You want the bunk to be just a bit past the edge of the
transom when the boat is on the trailer. The engine and transom are
where the most weight it. Also make sure you have them when the hit a
flat part of the hull if it is not flat everywhere on the bottom.
They will bend to fit as needed if you have them positioned ok. Some
trailers have 4 but for most boats 2 is enough. I only have 2 10' 2x6
bunks for my 19.5 with a 5.7.