Which Sander To Prep Bottom?

[Sid at SailAway]

Gathering together what I'm going to need for haulout sometime in April and need some advice on a suitable sander to prep the bottom for paint. Do I need a dust catcher model?

[Ex-Calif]

Dust catcher may depend on the boatyard you haul at.


We did ours with 2 Bosch orbital sanders and good quality 3M 120 grit paper.


We were simply applying Micron Extra over Micron Extra so just needed a bonding surface.


Depending on what you are doing it can get more complicated.

[44'cruisingcat]

You definitely need a way of catching dust, if you're going to dry sand. A vacuum cleaner attached to the sander is the best option.


If it's just a quick haulout and bottom paint though, you could wet sand using 40 grit wet & dry, a board and a hose. You'll get filthy, but that's a given.


It's not fun either way, but dry sanding is a PITA, because antifoul clogs paper very quickly, and even with a vacuum setup, dust still goes everywhere.

[Boatyarddog]

80 grit, your not painting a room.
Orbital is fine , wear your mask, multilayers 3 or more will make it last 5 yrs.
Micron with biocides, Interlux.
Tailcoat of contrasting color,for the first coat, then you'll know when your needing to repaint.
Also, extra passes on all "leading"edges, rudder, keel, waterline, bow chine.
Have fun !😄


Sent from my iPad SV Cloud Duster

[Sid at SailAway]

So it looks like an orbital sander is the ticket. Ex-Calif mentioned a Bosch, what model?

[Cheechako]

Definitely invest a few tyvek throw away coveralls and goggles or faceshield. If you are just cleaning it up to repaint orbitals are fine.. bigger the better. I'd probably do 80 grit, if lumpy/thick even 60 or 40.
The yards up here require the sole boat to be enclosed in plastic.


Definitely ask questions of the yard before you choose.. also ask if they allow outside workers. If not ask if they allow other family members. You can always hire your "cousin"... :>) You might get tired and want to hire a local guy cheap....


Last but not least.. ask if you have to buy paint from them.

[JAYEN1]

ABRANET is a 'sandpaper' that can be used wet or dry.
I use 80grit wet on bottom paint, 180 to 320 wet on varnish etc.
The bottom paint, I mostly do by hand with a 'doodle bug' type sander on a pole and a hose to keep it wet.
On a 50' boat I will use about 4 to 6 pads at a cost of about $1/pad.
These pads are available in circular or rectangular shapes(Velcro type backing).
It has an 'open weave' structure, so it can be used dry with a vacuum system.
This product is used in the auto repair industry and apart from myself I have never seen it used on boats......except by those people to whom I have recommended it.
You will never use anything else ever again.
I should be on a comm. from Abranet!!

[Sid at SailAway]

Ok, Google was not my friend...What's a "doodle bug" type sander? I have everything else, suits, masks, eye protection, etc. I'm going with West Marine Bottom Pro Gold which is made by Pettit. At the Port Supply price it seems like a no brainer...

[JAYEN1]

Ok, it is a flat rectangular plastic plate with a Velcro surface on one side. On the other side in the centre of the plate is a 'universal' type joint so that the plate is able to turn in any direction but stay in contact with the sanding surface. The uni joint is where you attach a screw-in telescopic pole (just like a paint roller).
If you cannot get the rectangular abranet pads, use 2 x circular pads, they will overlap a bit but will work just fine.
They rarely clog up, but if they do just wash/hose them out and keep going.
The more water you use the less clogging you will get...but you don't need a lot of water...just experiment until you get it right. I've even just dipped it into a bucket.
At the end of the process wash the used pads clean and you have some 120 or 180 so grit pads for your next project...and so on. I'm no sure if they ever wear out?

[Reefmagnet]

My brother runs a home reno business and absolutely swears by this style of drywall sander:



He reckons they will sand wet or dry and produce extremely low levels of dust which would make them perfect for sanding anti-foul.I've not seen one in operation or tried one, but they do look interesting

[Tingum]

The best sander is one in someone else's hand! This is a job worth hiring out! Said he who does most everything himself!

[misfits]

If all you want to do is "prep" the bottom for paint, I'd recommend a drywall screen attached to a broom handle. If you're looking to do a complete bottom job, orbital sander attached to a vac.

[Cruiser2B]

I have this job to do on my Alberg. Upon inspection of her hull I found 6-8 layer of paint and who knows what else before seeing gelcoat. I have been getting a majority off with a scraper. Dirty work and time consuming but scrapers seems to be way to go if you have several layers to remove. once i have most off I will use an orbital as other have suggested.

[Rhapsody-NS27]

Originally Posted by Cruiser2B

I have this job to do on my Alberg. Upon inspection of her hull I found 6-8 layer of paint and who knows what else before seeing gelcoat. I have been getting a majority off with a scraper. Dirty work and time consuming but scrapers seems to be way to go if you have several layers to remove. once i have most off I will use an orbital as other have suggested.

yeah, that's on my list too.

Getting any work done on the boat this winter?

[Cruiser2B]

Originally Posted by Rhapsody-NS27

yeah, that's on my list too.

Getting any work done on the boat this winter?

Not much, got shelter finished. Weather has been real cold so mostly finishing up a few engine projects and driving ferry. I'll start tear boat apart real soon