Mac 'bump' and silicone

[BOAT]

Store can so it does not start spraying in your car/truck while you are driving.

!!?? ?? Wow, there is a story in that line!? Okay, I will be careful of the stuff! Tanky Tanky very much!!

[Tomfoolery]

How is it applied?

Aim the nozzle at the bunk, and push it in with your finger tip. Move can back and forth to apply over an area, rather than in just one spot.

But seriously, look for the wear patches on the bunk carpet, and only apply there, so you don't waste it treating areas where the hull doesn't even touch. It's the patches that hold the weight of the boat when it's out of the water that need it, not areas that guide it on when it's floating. My trailer has two large patches on the rear bunks, and patches on the two little wing bunks, and smaller patches on the middle bunks and the little vee at the bow. Doesn't take a lot of Liquid Rollers to treat them, but she slides nicely into the bow cushion without having to hit the brakes so hard the trailer wheels lock up (just to get the boat to start moving, at which point it doesn't want to stop) when I do treat them.

[BOAT]

Excellent - I like!

[Steve K]

I did Tahoe Jacks mod on both my 26X trailer and now my 26D trailer. This solves the problem on both boats. No more bump

http://www.macgregorsailors.com/modt/index.php?view=547

You do need to use a tie down strap from the bow eye down to the trailer tongue to keep the bow from bouncing on the road. Or as I did, installed a giant turnbuckle from the bottom of the winch tree that will reach the bow eye.
Now all I have to do is crank the boat up into the bow notch. Then before traveling I pin the big turnbuckle into to the bow eye and tighten it too. Way better than all that Mac bump stuff .

I've used "Liquid Rollers" on the bunks for years and several boats. My 26X had the best bottom...... smooth and silky. And yes, it would slide around on the trailer, if not tied down. It would even want to slide off the trailer at launch ramps. The key here is to keep it winched up good until she's in the water, when launching. and be sure to winch her up when recovering at the ramp.

I have seen boats and jet skis slide off their trailers more than once at launch ramps....... never my own though...... okay so far.

Best Breezes,
Steve K.

[BOAT]

I would be concerned about removing that much material from the trailer bow chock bar.

[Russ]

I would be concerned about removing that much material from the trailer bow chock bar.

The M's aluminum trailer is a bit different. Not sure how this mod would work on it.

The slippery stuff seems like a simple solution. Could also get a bunch of friends at the ramp to get behind the boat and give it a big shove onto the trailer.

[Steve K]

I would be concerned about removing that much material from the trailer bow chock bar.

I was too, when first considering doing it. However, I've never experienced any ill effects on either boat/trailer. The metal on the sides is pretty thick. I thought about welding extra plates on each side, but never have needed to. And believe me, I have put some stress on the winch and the strap. I think the winch strap would break, before one could bend the winch tree. That or pull the bow eye right out of the boat. (I have a larger bow eye than the original that is highly reenforced inside the boat too)

Last time I had the boat out (too long ago), I launched at a really shallow ramp. Recovering the boat with the ballast tank full (you just can't power the tank empty with the D boat like you can with the X) was problematic. I had to pull out the winch strap near all the way as I couldn't back the trailer in far enough to float the boat onto the trailer. I ended up cranking the boat up onto the trailer using the winch. It was a lot of work and I was a little worried about my winch strap, as it is old and sun damaged near the hook.
Anyway, after muscling the boat back on the trailer that way, I have no worries about the winch tree, the winch or the bow eye. I will be getting a new winch strap though.

So, I would say if you want to do this mod, it is not a problem at all.
Hope this was helpful.

Best Breezes,
Steve K.

[tlgibson97]

The bump has never worked for me. I have liquid rollers but I haven't applied it yet. I would like to get a safety chain installed before I apply it.

Right now, the best thing I have been able to do is just put the trailer into the water far enough so that the eye is at the correct level with the V-block. I then grab the trailer guides as the boat is being pulled out to ensure it lands centered on the trailer. There's so much friction on my bunks that the boat won't even slide down and center itself. There's been a few times I pull out and a tire is rubbing on the hull.

[BOAT]

Yeah Steve, I think it would work and the metal is probably strong enough. I don't trust ME removing that much material from the bar.

I would probably screw that up. Still, it's an idea I'm looking at. I'm still trying to draw it up like you described. I still don't understand the geometry.

To me the geometry says that even if I get the boat tight into the chock at the ramp the chock will move away from the bow as soon as I pull the trailer onto level ground. I still can't see how this all works without moving the chock.

It just seems to me you need to move the chock to make the geometry work. I will do some experimenting - I just want to stop the bumping routine.

As I recall the very first time I retrieved 'boat' out of the water the bow did not move away from the chock. On that day I emptied the ballast before retrieving.

That might be a hint.

[Steve K]

Boat,

****************Remembering I can't speak directly on the M, as I only spent time on one while helping out at the Vegas boat show once.*****************

You are correct that an empty ballast tank does help in recovery.
As far as the geometry goes....... remember, the trailer flexes some when loaded, which changes it. A ballasted boat will flex the trailer even more and then emptying the ballast on the dry, changes it once again. So the geometry is inconsistent enough to make a difference in where the boat ends up on the trailer.

But the main thing I found is that the angle of pull on the under mounted winch is the main problem. You can only pull the boat up to a point with the winch as it is mounted, then it pulls down on the bow, rather than forward.
With the winch mounted in the new position, when you crank the boat in that last few inches, the winch lifts the bow and pulls it into the bow chock nicely. With my D and my X, I could actually pull the bow up too tight, to the point that when on level ground the boat would only be contacting the trailer on the bow chock and the rear bunk. This was an easy thing to deal with though as just backing off the winch a couple clicks and driving a mile or so, the boat will settle into place.
Sometimes, after parking on level ground (after recovery and ballast emptied, I will find the bow not contacting the rubber bow chock (an inch or so away). With the winch mounted in the new position, I can actually crank the boat into the chock, because of this lifting action (as long as the bunks are still wet.... it's much harder if everything is dry).

I think the winch was mounted @ the factory in the way it was to keep the bow from bouncing up and down during trailering down the road. This way they saved a few bucks by not having to add a secondary hold down of some kind @ the bow.

Anyway, to solve this problem, I think this is what works best of all the mods I've seen. I'm sure some trailer shop or metal work place would be willing to do this for you, for not to much $$ if you don't trust your skills.

OH..... and I like the winch crank being on the right side and cranking the right way too



Best Breezes,
Steve K

[BOAT]

Steve,

I think you hit on the answer - YOU DID IT! I think your post made me think about this in a different way, and now because of your post I think I know HOW to AVOID the MAC BUMP and make the boat come clean out against the trailer chock!

Here is the answer:

Step one: Bring the boat into the trailer as usual and crank it in.
Step two: Pull the boat up the ramp out of the water and let the ballast tank drain.
Step three: Walk to the back of the boat and CLOSE THAT BALLAST GATE!
Step four: BACK THE BOAT BACK INTO THE WATER!!!
Step five: Re-Crank the boat all the way up to the chock!

This is only theory but I can't wait to try it!

Anyone ever try this??

How would empty ballast change the picture that was drawn by Tom?

[mastreb]

Steve,

I think you hit on the answer - YOU DID IT! I think your post made me think about this in a different way, and now because of your post I think I know HOW to AVOID the MAC BUMP and make the boat come clean out against the trailer chock!

Here is the answer:

Step one: Bring the boat into the trailer as usual and crank it in.
Step two: Pull the boat up the ramp out of the water and let the ballast tank drain.
Step three: Walk to the back of the boat and CLOSE THAT BALLAST GATE!
Step four: BACK THE BOAT BACK INTO THE WATER!!!
Step five: Re-Crank the boat all the way up to the chock!

This is only theory but I can't wait to try it!

Anyone ever try this??

How would empty ballast change the picture that was drawn by

Unfortunately, it doesn't work. When you re-float the boat, the angle to the winch goes right back to the same as the CAD drawing, so even with it drawn tight the boat will have to pull out more strap from the winch as the stern settles back on the trailer.

Tried it

[Russ]

BOAT, save a few steps and drain the ballast before you get to the ramp.

Still won't work as this is how I do it.
Once the boat comes off the ramp and lays flat on the trailer, the winch doesn't line up. (See diagram above) We find the Mac bump a fun thing to do. Also tests brakes and makes folks in the marina wonder what we are doing.

I'd use that lubricant stuff except I like jamming on the brakes and testing for when an antelope jumps out in front of me.

[BOAT]

Yeah, but your not towing with a motorhome with a fully stocked wet bar and crystal.

My Marina is too small to drain the tank. We can't go blasting around in Oceanside Harbor at 13 knots - it's not allowed and there is no room, I would need to go back and forth to get all the water out.

I don't drain the boat out in the ocean because the entrance to Oceanside Harbor is a shoal break with REAL WAVES and shallow water so it's much safer to come in under sail with a stiff boat or you get knocked around pretty good. It's not always that bad, but it's that bad often enough that I don't want to dump my ballast until I get in the harbor, and then there is not enough room to blow it out.

Getting the water out on the ramp is SO much easier.

But, like you said - it sounds like that is not gonna solve my problem anyway.

[mastreb]

Yeah, don't drain before coming into Oceanside.

Here's what I think amounts to your only real solution: http://www.powerwinch.com/powerwinch/co ... tegory&c=1