Hey, that is what we are doing as well (I am the only one in the group who dares to apply the belt sander): http://woodastic.blogspot.com/2008/03/repeat-until-done.html

I use an orbital sander afterwards with a soft foam pad. Then a quick run over the hull panel with a torture board. Thinking is that we will fair the underwater hull "the hard but proper way" with fairing compound and put on some graphite when time permits.

It’s definitely not the Zen way to do it…but if you want to “gett’er done”…A low speed (under 1750 rpm) heavy duty sander/polisher with an 8” diskkit is much faster than a belt sander but it requires a very skilled operator…lack the skill, choose the wrong grit paper, or stop for in instant in one spot and you will have major problems...In the right hands it will cut your time to a fraction of what a belt sander will take. In the wrong hands it will destroy the fairness of a boat in minutes. You have to constantly stop, step back and LOOK at the work.

When I was building custom million dollar yachts (65’-105’) in the eighties the only thing we used belt sanders for was sharpening our wood chisels when it was too far to walk back to the shop to use the bench grinder…LOL. Sander/polisher> 6” DA> long board…The awl grip hulls of our boats were like a mirror.

Regards,
Bob

Hi Rolf
When i was finishing off my first boat,Phil went into panic mode when i mentioned the belt sander,and as he said alot of water has gone under the bridge and with practice you do get better Ha Ha. But he still does cringe a bit when i mention the B word.And as for stripping paint(industrial 2 pak) you can't use anything else.

Rolf, just sent you a Private Message, thanks. Tim

The key to using the belt sander is to never ever stop moving it around, and run it paralell to the fibers, never across. That is my technique, and minimizing stops/starts, as they always seems to leave a mark.

How many watts would a "heavy duty polisher/sander" be? What is a 6" DA?

Bob,
That method worked well on the inside of the 32ft cat hulls I built. Hell that was nearly 20 yrs ago.
I tried to upload a pic of the inside of the hulls but that has changed with the new upgrade. Looks like you already need the pic on a server ?

Dual action sander. Circular or random orbit. The 6" DA is a very powerful tool for working large areas. There is also an "inline file"; air driven version of the long board, for finer work.

Rolf,

I used the belt sander on the outside of the Alfresco 920 @90 deg to the planks and it worked well. Although the fine cedar dust used to get into the sealed bearings and I went through two sets of bearings in the sander. Using 90 deg probably wouldn't be suitable on thin planks as it rips the wood back pretty quick.
The sander polisher, I used on the inside and it worked great, It had a foam disk of around 7 or 8 inch dia.

Richard,
The belt sander is all very well on cedar planks that are 11mm thick but when you pull out a belt sander to use it on ply hull where the first laminate in the ply is around 1mm thick. I can't help myself.

Phill, I just like to do it to get the horrified look on your face,and agreed Rolf if you stop you end up with an inspection hatch that you don't really need

Sleeping less means more building done at late nights. Panel #5 (of 12) is now almost ready for sanding and glassing. Love christmas! http://woodastic.blogspot.com/