Painting and sanding hull safely

[Karnic]

Hi guys. Need some advice on painting and sanding hull safely.
1. Hull is brand new. Going to use a random orbital sander. What grade of sandpaper would you suggest?
2. Would do this work with boat sitting on a roller trailer. Trailer consists of 4 roller arms with 6 rollers per arm. no keel rollers at all. In order to work comfortably I am planning to use this technique. Please help.
1. Sand all boat except roller areas
2 when finished will put a boat stand near arm roller A( Already sanded where I put stand) remove the roller arm A, sand the roller arm A area , re install arm A, remove stand and move to roller arm B and use same technique.
3 Will tie down port side to trailer if I am working on starboard side roller areas.
4 Also would do some wooden blocks under keel when preparing to remove arms.

Do you think I will be safe to work underneath hull with removing one roller arm at a time? could not remove boat from trailer due to lack of garage height and not much tools to work with.

 

[BruceK]

Why remove a roller arm which may be under tension and difficult to put back? I'd roll the boat back slightly. Hitch the trailer to the tow vehicle if there is any chance it might see-saw / flip or use axle stands at the back of trailer to achieve the same.

 

[wellf100]

Not sure how big your boat is but on my 17 footer on a roller coaster I just put some blocks under the end of the trailer to stop it tilting. Painted the hull, then rolled the boat back 10cm or so on the winch and painted the gaps and then winched it forward again once dry.

 

[jimmy_the_builder]

Why remove a roller arm which may be under tension and difficult to put back? I'd roll the boat back slightly. Hitch the trailer to the tow vehicle if there is any chance it might see-saw / flip or use axle stands at the back of trailer to achieve the same.

If it's a rollercoaster trailer with an array of rollers, the OP will need to roll the boat back a couple of feet, so the over-balancing risk is a bit higher - but that said, I agree with what you're saying here and I'd do the same.

 

[mlines]

If its a brand new boat on a trailer, why are you painting the hull??? Will hold its value much better with a clean, shiny hull and would still be fine after short holidays in the water?

 

[longjohnsilver]

If its a brand new boat on a trailer, why are you painting the hull??? Will hold its value much better with a clean, shiny hull and would still be fine after short holidays in the water?

Exactly what I was thinking! If op is talking about a/f then all he needs is a primer. If he's epoxying then sanding gives a good key, but why epoxy a trailer boat?

 

[Karnic]

Have to put AF because boat sits on water for 3 and a half months and locally ( Mediterranean ) it is a high fouling area. My concern to roll the boat backwards, paint and then move forward again is because im afraid that with the weight of the outboard moving the boat backwards may cause the boat to fall from the transom side. Am i right or im making a mistake?