Trailer dance? (working on hull)

[tidalwave]

I need to raise the bow of my 26M slightly while on the trailer ... I need to work on the hull where it is supported by the forward bunk. I only need about 1 foot of clearance. I am worried about trying to lift the hull and placing upward lift in the wrong spot on the hull.

I thought about placing hydraulic jacks on either side of the hull pushing on a 4x4 timber which supports a piece of 3/4 plywood, which in turn supports two small rubber tires, which are in contact with the fibreglas. There would be a small open space at the keel line between the tires.

If you think this will work, an negative ideas about the positioning of the tires, etc? I don't want to crack the hull...

[Paul S]

Funny I was thinking the same thing.

I need to repair the bow bunkboard, since it almost sheared off last year. I bought a 8" roller to put in front of the bunk board so (hopefully) it won't happen again.

When we had a powerboat. I just put a block of PT on the keel and used a bottle jack (or 2 or 3) to lift the area (or the boat) off the trailer.

Haven't got to that mod yet..it is on the list though.

One other thing you/we could try. I did this and it worked 'enough' to do what I had to do...

Block the tires of the trailer well. Put the trailer jack on a 2x4 scrap (I use PT). raise the trailer jack as high as it can. (make sure your motor is up). Block the keel with wood. lower the jack and the boat should stay on the stack of wood just above the trailer. Remove the block from under the trailer jack for another 1-1.5". Haven't tried it on the mac, but worked on our powerboat.

Paul

[tidalwave]

Using the tongue jack and a stack of wood and rubber tires aft, then lowering the jack is a great idea! Thanks...now I won't have to jerry-rig two piles with hydraulic jacks...

But I am still in a quandry about where exactly to place my temporary pile.

[Paul S]

I usually just put it where the keel was somewhat thick. Never had a problem on the powerboat. I assume the mac keel is strong enough to take the stress

For the most part...you are just taking a lot of the weight off the tires..so you probably won't get stellar clearance..but it should be good enough

Paul

[flbum]

I don't know whether you want to bottom paint it or have a hole to fix, but
here is a far out naive idea...

Can you float the boat (without it sinking) before you do the work? If so, buy a can of MaryKate Liquid Rollers. I discovered this stuff from some previous posts on this board. The stuff is great! I'm able to winch my boat up onto the trailer with most of the front bunk out of the water. I'm able to easily winch the boat into the rubber V while on level land without doing the "Mac bump".

Do you see where I'm headed? If you can float the boat, you can treat the trailer bunks with this the Liquid Rollers. Then you can put the boat back on the trailer, but not all the way forward. Then you can do the work and winch it up snug later. This might work for doing work under the front bunk because it is perpendicular to the length of the hull. It wouldn't work for working under most of the the rear bunks because they run the same direction as the length of the hull.

If you don't want to use the Liquid Rollers, you might just be able to re-float the boat to reposition it afterwards or do the "Mac bump" .

Perhaps this a naive solution, but I'm lazy and this seems like it might be the easy way to solve this problem.

Regards,
ROB

[tidalwave]

I am planning on putting a vinyl Keel guard strip onto the new hull... the strip has to go on to an absolutely clean fibreglas surface... so it has to go on before the first launch and before any bottom paint or coatings go on (for best and longest adhesion). The problem is...the strip is 9 feet long from bow towards the dagger board, and has to be applied past the front bunk. The adhesive is so powerful that you cannot just slide the strip in the space between the bunk and the keel...if it sticks incorrectly...it's there forever. So I need enough clearance between the keel and the bunk to carefully unroll and apply the strip.

Some of the lakes I am going to sail on have beautiful sandy beachs...I want to be able to gently bring the Mac up to the beach...so we don't have to use the dingy or swim to shore. But I also don't want the keel to rub on the sand directly...so I am putting a KeelGuard strip along the keel to protect it.

If I want I can then coat over the vinyl strip with bottom paint etc.

[flbum]

Well, I guess that my idea wouldn't apply in this situation.

I had considered bottom painting originally and my solution might have worked for that. I had trying to float the boat on a little heeled to solve the problem of painting under the rear bunks. I don't know if that is practical.

However, after a little experience with the boat, I believe that bottom painting isn't really necessary unless the boat stays in the water for a long time. Even after two nights in the water, it wasn't that hard to brush the scum line off with a car washing brush.

I haven't beached the boat yet. However, I was a little concerned about the abrasion problem as you are. I was also concerned about tides, wave action, etc. So, I decided to just anchor in shallow water and walk into shore in (hopefully) knee deep water rather than beaching the boat. This is still academic for me as I have not reached the point of having this experience yet, at least not on our Mac.

Good luck with the vinyl installation.

Regards,
ROB

[DLT]

1. If you're thinking about "bottom paint" then you probably know that the first step is actually a barrier coat of epoxy. If it were me, I'd want to put the barrier coat on the boat itself, then apply the keel guard, then apply the bottom paint. But, I know you're anxious to get the boat in the water. So, if it were me (and this is actually my plan), I'd just go ahead and use the boat as is for the first year. Accept the sctraches, they'll get covered. Over the winter, you'll have time to do all these little chores (or pay someone else to do them {of course, since its cold in the winter, you may be forced to pay someone with a heated garage to do this stuff}).

2. BE VERY CAREFUL THE BOAT DOESN"T SLIDE OFF THE BACK OF THE TRAILER. The bare boat (no motor) is pretty well balanced on the trailer. But, as soon as you hang a motor on the back, the center of gravity shifts more rearward. Anything, such as putting the boat more rearward on the trailer or tilting the boat with respect to the trailer, that moves that center of gravity even more rearward can be dangerous.

Alternatively, what you might do, is use the trailer jack to get the bow as low as possible, thereby rasing the stern. Block the stern off. Your plan of using tires (off the rim I assume) sounds like a good idea. support those tires with wood, and be sure to make it real stable. Then, use the trailer jack to lift the bow as much as possible. Here, given your task, I'd suggest putting support under the dagger board slot. That area was specifically reinforced to make the dagger board itself fail first. So, its likely the strongest part of the hull. Again, use tires and wood to spread the load and give stability. Then, drop the trailer back down. If needed, you can put the trailer jack on blocks and lift the bow some more...

Of course, block the wheels first, from both directions.

Now, the boat ought to be resting on the blocks, and not the trailer... To me, this seems safer than halfway resting on the trailer and halfway not...

And the trailer is under there to 'catch' the boat before it crushes you. Also, be quick about any of the work which puts your hand/arm/etc between the boat and the trailer, justincase...

[Chip Hindes]

I've lifted the boat off the trailer on a number of occasions. I put jack stands under the trailer rails at the stern, a short piece of 2X6 under the keel just forward of the centerboard well, and jack the bow off the trailer. I use a 5-ton floor jack (one of the best investments ever for those who do their own work). I don't care for bottle jacks; too unstable. Obviously you could use wood blocks instead of jack stands under the trailer rails, I just find jack stands more convenient. I never use cinder blocks to support weight. That's asking for trouble.

If I'm going to be working between the boat and the trailer, I put a couple pieces of 6x6 I had left over from a deck building project under the keel.
This is stable and does no damage.

If you only need to do this for a short time, leave the trailer attached to the tow vehicle to hold the tongue down, and you don't need the jack stands or blocks at the stern.

[Joe 26M Time Warp]

Or, if you're too worried about it, see below:
Careened by Steve K.

[Hubert]

I lift mine using the suggestion from a post on the old board.
Block the wheels. Drop the nose of the trailer as low as possible, place a support ( I use my sawhorses) on each side at the rear and place a piece of 4X4 accross under the the boat resting on the 2 supports. Crank the nose of the trailer as high as possible, this will lift the back end of the trailer. Now support the front with another 4X4 and supports. Drop the nose of the trailer and the boat is now of trailer.
Hubert

[dclark]

To get the bow off the trailer bunk..

Jack the trailer up as high as it'll go, loosen the winch a little so there is some slack in the line, place s few blocks under the bow arranged in a place that they almost touch the boat but leave an inch or so gap, fill the gap with something soft (card board strips or a piece old carpet is perfect), then crank the trailer jack back down. You'll now have several inches of clearance between the boat and the trailer bunk.

[tidalwave]

Thanks for the helpful suggestions. I used a large hi-lift jack to raise the trailer upward, left the winch strap still attached to the bow-eye (but very loose so there wouldn't be any downward pull when the boat hull was actually supported...didn't want the hull to slide backward)

When the tongue was high enough...I cranked the tongue jack back down on a raised cement block pile...didn't trust just the hi-lift jack to hold everything up.

The hull support was made of several layers of cement block, with a plywood cover, then a rubber tire (no wheel!) was placed on top and then the tire was covered with a cloth to keep the rubber from marking the hull. I placed the hull support partially under the daggerboard slot and partially forward (there is a cross rod on my 26M trailer to keep the daggerboard from dropping down on the road accident, which kept me from putting the support completely beneath the slot).

I slowly lowered the tongue and with a little groaning from the tire, the tire slowly deformed around the keel...but no sounds came from the hull. There was so much friction on the rear bunk that the hull did not move visibly at all.

I then had about 1 foot of clearance of the keel above the forward bunk. I could then clean the hull and install the keelguard.

After finishing, I reversed the process and carefully checked the hull for any warping...none visible.

By the way...vinyl Keel Guards cannot be installed on bottom paint...the 3M adhesive must come into contact with a clean hull...the vinyl strip will just slough right off carrying with it most of the bottom paint.

I had to decide which to do first...and the KeelGuard was a higher priority for me. Bottom paint should adhere to both the fibreglas hull and the keelguard vinyl when it is applied.

[Chip Hindes]

You're asking for trouble, using concrete blocks to support anything other than the foundation of your house. Their not designed to support, cars, boats, or anything else of that nature.

[DLT]

Against my better judgment, I just gotta reply...

Hey Chip,

Blocks are good enough for the rednecks...


Just joking here... Please hold your flames...