Lifting off a trailer?

mwb.wright · 11 October 2016, 11:19

Sorry to pester again, I've searched on here but can only find lifting points relating to constant use with proper brackets etc.

I recently bought a very tidy SR4 which i'm currently doing a few jobs to make perfect (OCD

) and now i'm stuck.

I want to lift it from the trailer so I can get underneath it to repair a very small chip and fully polish the hull (G3?) removing some very faint scratches also.

I have a two poster ramp at work so my plan is...

Run a strap under the bow, through the stainless eye on the front so it cannot slip.
Then run another strap under the engine in between the transom and engine and fasten both straps to the arms on the two poster ramp then send up.

How does this sound for maybe a few days?

I'm concerned that it would put to much strain on the center of the boat lifting so far forward and back.

Would more straps be needed or is this OK?

Lastly, Would I keep the tubes inflated or deflate - bearing in mind the straps would be resting on them for the duration.

Many Thanks.

spartacus · 11 October 2016, 13:05

It's not essential to lift the boat. The bare hull is 170kg, say another 90kg for an engine up to 50hp. I wouldn't use the bow eye to lift it, it simply not designed for that. If it were me, I'd move the boat onto tyres and old carpet and work on it on the ground. Remove any top deck furniture and with the help of a few friends, flip it over. That gives you full access, and you can work safely.

beamishken · 11 October 2016, 14:20

I've lifted boats on two post lifts loads of times usualy just put the pads under the chines fore and aft and lift it up no need to bother with straps

jyasaki · 11 October 2016, 15:08

Alteratively, put the trailer on blocks (to get room to work underneath), do as much of the bottom as you can, then jack up the front and back (not at the same time) and shift the boat on the trailer a bit to catch the parts you missed. That works better on bunks than rollers.

If you want to raise it, a block under the transom and a V-shaped block about a third of the way back from the bow should do it. I just use an automotive floor jack, then block it up on jack stands. Be careful, as it will try to tip (I use ratchet straps to the trailer frame to keep the boat from tipping. Same as before, when you need to get to the part the blocks cover, let it down, move the blocks and raise it up again.

jky

mwb.wright · 11 October 2016, 16:02

Thanks for the replays so far!

I'm not wanting to flip it etc as I do t want to remove the engine and havnt got the lock for the engine lock anyway.

I wouldn't be lifting it from the front eye I would only be feeding a strap through it and the strap would be around the whole front bow. It would be through there to stop it from any slippage.

I thought about doing the work on the trailer etc but though I'f it was safe enough to do as I said above then I could polish it all in one go and have the whole hull 5 foot in the air to see to it and work on it properly.

beamishken · 11 October 2016, 16:13

I've done exactly what you want to do with just the lift arm pads under the chines as long as the lift arm locks work it's fine sometimes need to do a couple of trail lifts to get the ballance as it's surprising how far the centre of gravity is to the stern
If the lift has asymmetric arms put it on backwards
If your worried I guess you could work out some way of cargo strapping the bow and stern eyes to the lift arms to prevent the possibility of tipping it off the lift

mwb.wright · 11 October 2016, 17:03

Quote:

Originally Posted by beamishken

I've done exactly what you want to do with just the lift arm pads under the chines as long as the lift arm locks work it's fine sometimes need to do a couple of trail lifts to get the ballance as it's surprising how far the centre of gravity is to the stern
If the lift has asymmetric arms put it on backwards
If your worried I guess you could work out some way of cargo strapping the bow and stern eyes to the lift arms to prevent the possibility of tipping it off the lift

I've never thought of actually using the lift arms instead - I guess it would put no stress on the tubes doing it this way as well!

Yea, the arms do lock actually so that could be a better plan and like you say put it on backwards.
Would have to look into how to strap it on the lift safely though in case it was to slip.

Are the chines flat enough to sit happyily on the lifting arms though?

beamishken · 11 October 2016, 18:13

Yeh sr4 chines are quite flat and prety wide too so should be fine