The Porter Cables will eventually start to squeal and burn out too. They don't like being upside down with copper being sucked into them. At my friends boat yard they get three to four years out of Fein before it needs to be sent out for repair. The Porter Cable machines 94766 etc.. are on a rotating basis and get 4-8 months.... Sanding bottom paint is a death sentence for ANY sander it is just a matter of time. For the average DIY doing it once per year a Festool or Fein will likely outlast you. A Porter Cable will get you maybe 10+/- sandings, I've killed them in just two as it depends I suppose on the copper content of the paint............

Yes the Festool or the Fein will be MUCH faster. They also extract dust far better and last longer. Their sand paper actually lasts longer too. Copper paint chews through cheap home center quality sand paper....

If I was buying right now it would be the Festool sander and vacuum. They don't gouge you on paper nearly as badly as Fein does but both are tremendous products that DO make a difference.

Don't discount the vacuum as an integral part of the sander, especially with Festool. The variable speed allows you to keep the pad spinning on the surface which speeds up work and dials pad rotation to balance perfectly with dust extraction. With a standard shop vac they tend to "over suck" and stall the rotation of the pad by sucking it to the hull far too hard. This both kills performance and eats through paper. A router speed control on a cheap vac can help but is not the best substitute for the complete Festool system. I am slowly investing in Festool and have been using Fein products for years. On of my favorite things Festool sells are the Velcro backed Scotch-Brite pads for the RO sanders. I use them on my jointer, table saw, band saw and drill press cast iron tables to keep them shiny & rust free. They also work way better than sand paper for anual spring "touch up" for the bottom paint to "rough it up"....

They are truly superior products in every way, but you do pay for it...... With my Porter Cable 5" I finally threw it away as Sears stopped honoring my "lifetime warranty" that I paid extra for... BEWARE of the Sears "extended lifetime warranties" they are NOT worth the paper they are written on. I switched to Rigid for a cheap 5" RO and am on my second one with no questions asked...

 

I've been using a hepa filtered Skill brand POS... it's a 1/4 sheet sander. It has a vacuum assist into the hepa canister, and works OK... but now I've dropped the canister on the concrete floor and it no longer holds on the sander. It looks like it's also setup to take a standard shop-vac connection. I'll find that out soon. I suspect the sander won't live much past doing the boat. But then I could be wrong.

I CAN say that it's kept a decent portion of the dust down into the canister, at least until I broke the canister.

I guarantee the Porter Cable covers more area. Although this little guy seems to take lots of pressure.

 

Festool...I rent it from our Marina anytime I want to sand the bottom.

 

For a scuff before a new coat I've been using a DeWalt 1/4 sheet sander for 20 years (plus other shop use). I use a vacuum with a very long hose (25 feet of the very cheap Home Depot corrugated sump pump hose--very light); because I have cats I can set the vacuum in the center and reach the whole boat.

For paper I use drywall paper. It doesn't last very long, but the vacuum is very efficient and it positively resists clogging with soft paint. About 4 sheets with my current boat. It makes for a very neat workplace.

Because I run the paint for 2 years and scrub a few times, I never get build-up and thus only a scuff is required.

 

I'd say since he's just brazing VC-17 (which is very hard paint), he should be looking for metal paper... 3m sells paper with a "sticky" backing, I've been using, but I'm taking off ablative, so it's probably not the paper for you... I've yet to have paper slip though. Purple grade I am using, I think they make some for automotive that'll do the trick to braise VC-17 for another coat. I can't imagine you needing to take the 17 off though, just rough it up (since it's such a thin layer when applied) and it self-levels.

 

Yeah I am just looking to rough it up / smooth it out for a new coat. Its thought to invest 500+ dollars into a sander for limited use. I never thought of automotive paper vs the lowes version I have been using.

 

Not sure how it would work with bottom paint, but a friend highly recommends Norton "3X" sandpapers for long lasting and non clogging....

 

During my wood working days we went thru a lot of random orbit sanders until we upgraded to Fein and festool. Not only are they faster; they last A LOT longer. The finish is much better as well. It's a day and night difference when compared to other sanders.
Can you justify the cost?
Fein Air Random Orbit Sander Models MSF 636-1 M10000-6 - Walter Tool Company

 

Something to keep in mind if you are only doing your own boat once a year - you can buy 10 or 12 cheap R/O sanders for what a Fein costs. I got several years out of a De Walt and right now I've got a ROK that cost me all of $35. I use Swiss Klingspor disks and they work great.

One thing I've noticed over the years is that very many people start at way too fine a grade of paper - 80 or even 100. I do most of my sanding with 40 grit and finish with 80 on the bottom. R/O's leave a much finer surface than the same grit by hand. I also longboard my bottom with the pictured body "file".

 

ditto on norton 3x paper.

 

I'm a little surprised that all the respondents to the thread speak only of dry sanding. I have anti-fouled my own boats for nigh on 30 years and have never dry sanding one square inch.

To be more specific, in the marinas, both in South Africa and here in New Zealand, dry sanding is pretty much banned because of the dust it generates and only wet sanding is permitted. Is there some rule in your areas that prevents wet sanding?

So my boats get wet sanded with a 100 grit water paper on an oscillating pad attached to the end of a broom stick that has a constant water feed to the paper via a tiny (mini irrigation type) hose pipe. If it sounds complicated, it is not, actually very simple.

I can reach almost all surfaces without stooping under the boat - very easy on the body. And I flat down the whole of my 44 ft boat for an anti-foul repaint in about 3 hours without any assistance and the finished job is always excellent.

Cost to rub down? Well the initial cost of the sophisticated equipment described above is about $30. From then, each rub down costs about $18 for the water paper. And water paper doesn't clog - it just wears down after a while.

 

I'm a little surprised that all the respondents to the thread speak only of dry sanding......

So my boats get wet sanded with a 100 grit water paper on an oscillating pad attached to the end of a broom stick that has a constant water feed to the paper via a tiny (mini irrigation type) hose pipe. If it sounds complicated, it is not, actually very simple..... .

Links or pictures, Andre? Around here you are required to tarp up and vacuum sand.. I've never seen anyone power-wetsand but it does sound like a great solution...... we'd probably have to catch the effluent somehow....

 

I have done a lot of bottom sanding with a Dewalt R O and it is still working well. However in my opinion if you are putting on VC-17, it goes on so thin, I see no reason to sand it off.

 

We had to strip off the layers of VC17 to put a salt water compatible paint on last year. The epoxy base of the VC makes it extremely difficult to sand with the Port Cable, but it helps if you can get down to a 36 grit paper. Like others have said, VC17 is so thin that you really don't need to strip it off unless you are switching paints.

 

That's an interesting concept, but like other have said VC 17 doesn't really need any sanding.

I have it on my boat as well. All you need to do is rudder, keel, leading edge, and water line between coats. You are simply painting the sections of the bottom that get the most wear. Then the following year repaint the whole bottom. That way you wear down the paint and no sanding is needed. The face lift keeps you from possible build up, and saves you money in the long run.

 

Like some of the more recent posts, a buddy that has sailed all his life has told me that wet sanding is the way to go. Not wishing to mix electricity and water, I'm considering a straight line, air sander, as used in body shops. Add a convenient pipette hooked to a hose to dribble water onto the pad and it's all good!

I *do* like the idea of the drywall sanding pad, too; as I have a couple to hand.

My bottom paint is pretty good. I just hafta get rid of he barnacle "glue" and rough the surface for the next coat.

 

I'd use a D/A with a foam pad, not a straight line "air file". Those are made for flattening things, not compound surfaces. They're pretty heavy as well. They are the air tool equivalent of a belt sander.

 

OK then... thanx.. a D/A w/pad it is I *might* try it w/the drywall sander and 3M wet'n'dry first. I don't recall that screen d/w 'paper' is waterproof?? I know there's a restaurant grade water/oil proof grill cleaning screen made; but don;t know grits avail.