blocking up a hull
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Boat Maintenance
Forum Discription: Discuss maintenance of your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=50803
Printed Date: January-15-2025 at 2:40pm
Topic: blocking up a hull
Posted By: nobrainsd
Subject: blocking up a hull
Date Posted: July-30-2022 at 8:22pm
| I am having no luck with my search skills. Alas. I need to pull my trailer out from under my boat. I have a gantry to lift the front but need to make blocks or a cradle (what do I know) for the rear. I know I've seen posts about this... a photo would be awesome. I'm sure I'll work something out, but it's always good to benefit from experience :) No trees are conveniently located. |
Replies:
Posted By: Jonny Quest
Date Posted: July-31-2022 at 12:38am
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I used a 2 ton engine hoist to assist when I pulled the trailer out from under my 1994 SNOB. First, I dropped the tongue of the trailer all the way to the floor. That puts the a$$ end of the boat way up. Then, I created 2 stable support columns using concrete blocks (cinder blocks) with a wood "softener" on top. I had a column at the starboard rear and port rear. When the tongue of the trailer was raised, the rear of the boat rested on the 2 columns of concrete blocks and was a couple inches off the bunk boards. Then I used the engine hoist on the front lifting eye to pick up the front of the boat. Now, the boat was suspended by the engine hoist up front, and the a$$ end of the boat was resting on the concrete block columns. Then, I was able to move the trailer forward in increments while the boat was suspended. I just jacked, blocked and moved a section at a time until the trailer was out from under the suspended boat. Then I put 1 support under the keel just in front of the tracking fins. I used 2 more concrete columns (one on each side) just in front of the engine. Nice and stable. JQ
------------- Current 2003 Ski Nautique 206 Limited Previous 2001 Ski Nautique Open Bow 1994 Ski Nautique Open Bow Aqua skiing, ergo sum |
Posted By: nobrainsd
Date Posted: July-31-2022 at 12:03pm
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Thank you Jonny Q. I have experience blocking large vessels where you generally just block the keel and have side supports. Kind of figured that supporting the aft end on each side would be more appropriate for my 94 Ski Nautique considering the mid engine and shaft arrangement (nowhere to really block the keel at the back without pulling the rudder and maybe the prop). Will probably go with concrete blocks topped by wood and maybe some carpet. Was originally thinking of a wood cradle. Might be more work than it's worth but I do have plenty of wood right now. Like your idea of additional side supports. The last time we pulled our 32' Westsail (with a full keel) we scrounged through the yard we were at and added more side supports than the yard employed. Can there be too many :)
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Posted By: MourningWood
Date Posted: July-31-2022 at 12:12pm
Good plan. I can visualize all this except how does the trailer move forward with the legs of the engine hoist in the path? ------------- 1964 Dunphy X-55 "One 'N Dun" 'I measured twice, cut three times, and it's still too short!" |
Jonny Quest wrote:Posted By: KENO
Date Posted: July-31-2022 at 3:46pm
M/W I think the gantry that he has and the hoist that you're thinking of may look completely different from each other
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Posted By: MourningWood
Date Posted: July-31-2022 at 4:36pm
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I see...something better than my $49.95 Pep Boyz special... ------------- 1964 Dunphy X-55 "One 'N Dun" 'I measured twice, cut three times, and it's still too short!" |
Posted By: Jonny Quest
Date Posted: July-31-2022 at 4:57pm
You are correct -- the trailer has cross-members that have to be dealt with. In the very first step, the concrete block supports were BETWEEN the rear of the trailer rail and the rearmost cross member of the trailer. With the boat suspended, I could move the trailer forward 12" or so before the rear of the trailer rested against the support tower. Then, using floor jacks and jack stands, I supported the rear of the trailer, removed the concrete block column supports and moved the trailer forward another 12-18" or so. Then, I re-positioned the concrete support columns at the rear -- this time, BEHIND the trailer frame. I had to do this 4 or 5 times when each trailer cross-member that came up against a support. Loading the trailer back on to the trailer was just a "reverse" of the process. That's what I meant in my original post when I referred to "blocking, jacking and moving". JQ
------------- Current 2003 Ski Nautique 206 Limited Previous 2001 Ski Nautique Open Bow 1994 Ski Nautique Open Bow Aqua skiing, ergo sum |
Posted By: KENO
Date Posted: August-01-2022 at 8:04am
See what he wrote in the first post
What's a gantry? here's a link with some gantry cranes or you make a homemade one out of wood http://www.google.com/search?q=gantry+crane&oq=gantry&aqs=chrome.0.69i59j69i57j0i512l3j69i60j69i61l2.7997j0j4&sourceid=chrome&ie=UTF-8" rel="nofollow - link Wide enough to pull the trailer through, you block the back like JQ said, hoist the front of the boat up and pull the trailer out Then block it wherever you want to support the front while it's hanging there
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Posted By: mosinee77
Date Posted: August-01-2022 at 9:42am
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Kind of Hillbilly, but here goes.... Jack the trailer up so the wheels are off the ground. Block the back of the boat with wood cribbing (or cribbing of your choice). 2 ton engine hoist to the front lift eye (come in from the side of the trailer) and lift slightly off the trailer. Pull off the trailer tires and wheels. Lower the trailer bare hubs on to cheap Harbor Fright wheel dollys. Then pull the trailer out from under the boat to the side (that does not have the engine crane). Crib the front. You will need to be at least high enough to clear the trailer fenders.
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Posted By: KENO
Date Posted: August-01-2022 at 10:38am
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Pictures you say ..............
Here's a picture of gun_drivers boat hanging from 2 gantries  |
Posted By: KENO
Date Posted: August-01-2022 at 10:42am
That might work on your 77 CC trailer, but you might want to add in that he might need to cut off or unbolt any guide posts or crash bars on the trailer (on one side only) or lift the boat way, way up high. |
Posted By: MrMcD
Date Posted: August-01-2022 at 11:47pm
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When I sandblasted my 78 Nautique frame we used a tow truck boom to lift the entire boat up then set it down on about 10 truck tires. It sat there a few days while I got the frame done and then we reversed the process. The next time I did it my garage had exposed ceiling joists that were 2 1/4 x 11. I bolted a Eye bolt into the joists above my lifting points and raised the rear and strapped it up using a come a long then went and lifted the front . Worked easy. Rolled the trailer out for repairs. Now the garage is sheetrocked so I no longer have access the those heavy joists. Should have put a couple lifting hooks in before the Sheetrock went in., ------------- |
Posted By: nobrainsd
Date Posted: August-04-2022 at 11:42am
Sure wish my garage rafters were capable of supporting the weight. Yes, I have a gantry crane :) Would be great to have two, but it's not often one spots a brand new aluminum Vestil AHA-10-10 for $700 on CL. I was going to roll with the concrete blocks for the two rear supports, but was concerned with stacking 4 blocks stability wise. Could go wider with 8 blocks for each stack... but I do all sorts of other projects and decided to break down and buy some boat stands. $116 on Amazon with free Prime shipping. Stacking stands, so much easier to store than the blocks. Coming to me Monday. Support the economy?  |
Posted By: Watauga
Date Posted: August-06-2022 at 2:08pm
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I just made mine out of lumber with a pivoting top piece that contacted the hull. I used the trailer tongue jack by dropping the front of the trailer as low as the jack would allow and then installed the rear supports. Then jacked up the front of the trailer, again with the tongue jack, and cribbed under the boat with cinderblocks. Then began snacking the trailer out. I had to move the cinderblocks several times until the fenders cleared and to allow the trailer cross members to clear as the trailer was removed. I was working by myself, so I think it took an hour or so. When the trailer was finally out I placed the cinderblocks back under to offer a bit of additional support since I was in and out of the boat so much. I like gun drivers setup posted above by Keno, but I didn't have that much head-room or lateral floor space in my garage. I like that with his setup you could drop the boat to almost sit on the ground, with proper cribbing for solid support. If you are doing a total restoration you will be climbing in and out about a gazillion times, and that adds up for an old guy like me. 
   ------------- http://goo.gl/t8gAkI" rel="nofollow - 1980 Rebuild http://goo.gl/TFsgCy" rel="nofollow - Diary Signpainter, Disaster Responder, Longline Barefooter |
Posted By: gun-driver
Date Posted: August-07-2022 at 9:58am
Yep that worked well, I lowered it down to about 1 concrete block height (16”) for climbing in and out of. I also used the height adjustability to raise it so I could sit in a chair with wheels to wet sand and buff and then lower again to do the same under it on a creeper.
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