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Candyfloss
08-10-2009, 07:54 PM
Did I read somewhere not to use Stearate (Sp?) sandpaper on paint that will be painted over? It will fish-eye? I think this is the most likely cause of the problem I just had on my dinghy. Fish-eye on the first topcoat. I used Norton's Canadian-made "No-fil Adalox" to sand the undercoat. I've wet-sanded it off & recoated & it is o.k. But wet sanding is a pain. Literally. You can't tape up your fingers wet sanding & I'm bleeding from three of them. Is there a better way? Any advise will be apreciated.

S B
08-10-2009, 09:44 PM
Did I read somewhere not to use Stearate (Sp?) sandpaper on paint that will be painted over? It will fish-eye? I think this is the most likely cause of the problem I just had on my dinghy. Fish-eye on the first topcoat. I used Norton's Canadian-made "No-fil Adalox" to sand the undercoat. I've wet-sanded it off & recoated & it is o.k. But wet sanding is a pain. Literally. You can't tape up your fingers wet sanding & I'm bleeding from three of them. Is there a better way? Any advise will be apreciated.
What is stearate sandpaper? Stearate compounds are used as cheap extenders in paint. Didn't think you could make sandpaperout of it.

pcford
08-10-2009, 09:48 PM
Most professionals around here use 3M gold in rolls.

dmg
08-10-2009, 09:48 PM
As explained to me, the stearate additive to the abrasive is what make it "no-fil". Some of those particles are bound to remain imbedded in the finish, and may repel the next coating.

Automotive grade Scotch Brite works plenty good for scuffing between coats, and takes off less of your hard work. Otherwise, I think other papers are labeled "non stearated", open coat.

Dave

David G
08-10-2009, 10:02 PM
AFIK, you've got it turned 180 degrees. Stearated sandpaper simply has a coating over the grit that "lubricates" the sheet, and prevents premature clogging. This is most useful on a finished surface - as opposed to raw wood (unless an oily species). Sanding finishes is what the stearate coated papers were designed for. I've never heard of it causing contamination problems under any typical clear or opaque finish.

S B
08-10-2009, 10:26 PM
Oil paper as it was once called here,thanks for the refresher.

Ron Williamson
08-11-2009, 04:53 AM
Sometimes stearate paper messes with water based finishes.
R

RFNK
08-11-2009, 04:58 AM
You can't tape up your fingers wet sanding & I'm bleeding from three of them.


Why can't you tape up your fingers wet sanding? Rick

Canoez
08-11-2009, 07:48 AM
I agree with Rick. Self-adhesive gauze protective tape. Works when wet:
http://www.usplastic.com/images/products/handprotection/1612i.jpg

Should be widely available. Make one double pass over the finger tips, and then wrap around the finger tips to hold it in place. We used yards of the stuff to protect our assemblers from sharp brass parts at a place I once worked. Cheap, and effective.

David G
08-11-2009, 10:10 AM
Sometimes stearate paper messes with water based finishes.
R

Interesting. I could imagine that happening. The water-based concoctions seem to have much more complex - and vastly fussier - chemistry. However - I've sprayed a lot of Sherwin Williams Kem-Aqua, and brushed (on occasion) the Benjamin Moore water-based for years - and haven't seen any issues. What's been your experience?

Ron Williamson
08-11-2009, 11:42 AM
Not with paint.
Only clearcoat like Flecto Varathane and B-Moore, and between coat denibbing, not the first coat.
It seems to mess with the surface tension enough to be irritating,leaving what look like dry spots in the sheen.Not really even noticeable inside a cabinet,or after it's been re-recoated.
There could have been several other factors like a few drops of oil in the airlines,but it seemed to be better when I used different paper.
I did a whole kitchen in Baltic birch with water based clear and used about 5 gallons of it.
R

Candyfloss
08-11-2009, 02:59 PM
So the consensus is, it's not likely. Thanks guys. I'll have to look elsewhere for my problem.
Our market is flooded with Norton Abrasives. Maybe some reciprocal trade agreement, but 3M is available too. I'll go on a search. Thanks Mr. Ford.
I tried a sanding pad for the first time on this. Not happy. It shed grains of nasty sharp sand all over, followed the contours of the finish much too much, if you went anywhere near the edge of a plank it took the corner clean off, & went blunt in no time.
Rick, wet sanding,you can't see what you have done, so you have to go by feel. I'm ambidextrous sanding, use both hands alternately, so I have to tape up all six fingers leaving me nothing to feel the surface with. Besides the tape is slippery compared to the paint & you just sand your taped-up fingers, not the boat. Specially after turning the paper over to a fresh side, when you've got the worn side in your hand.

pcford
08-11-2009, 04:38 PM
3M paper is moisture and dampness resistant. Good thing around boats.

John B
08-11-2009, 07:52 PM
So the consensus is, it's not likely. Thanks guys. I'll have to look elsewhere for my problem.
Our market is flooded with Norton Abrasives. Maybe some reciprocal trade agreement, but 3M is available too. I'll go on a search. Thanks Mr. Ford.
I tried a sanding pad for the first time on this. Not happy. It shed grains of nasty sharp sand all over, followed the contours of the finish much too much, if you went anywhere near the edge of a plank it took the corner clean off, & went blunt in no time.
Rick, wet sanding,you can't see what you have done, so you have to go by feel. I'm ambidextrous sanding, use both hands alternately, so I have to tape up all six fingers leaving me nothing to feel the surface with. Besides the tape is slippery compared to the paint & you just sand your taped-up fingers, not the boat. Specially after turning the paper over to a fresh side, when you've got the worn side in your hand.


You can buy a hundred medical type gloves for $10 CF. You've probably got em for the epoxy. They work fine for fingers (wet sanding).

peter radclyffe
08-11-2009, 10:35 PM
i use surgical tape for fingers, or big plastic fishermans gloves

pcford
08-12-2009, 12:34 AM
I should have said 3M GOLD paper is moisture resistant.

Candyfloss
08-13-2009, 03:35 AM
Try the gloves. Thanks John.
3M Gold, Mr Ford.

Candyfloss
08-13-2009, 04:01 AM
So here is the vessel in question. I built a carry cradle for her today & brought her out into some weak, watery, NZ winter sunshine to take a few pics. Thanks for all your help.

http://pic50.picturetrail.com/VOL458/12377907/22018548/371810918.jpg

http://pic50.picturetrail.com/VOL458/12377907/22018548/371810574.jpg

http://pic50.picturetrail.com/VOL458/12377907/22018548/371810563.jpg

Next, fit out the interior & varnish. I daresay that will bring a whole new raft of questions. Ah well... My only defense is that as a fulltime boatbuilder (you could never call me a professional, although I've done this as a living for twenty years) we never painted the boats, just put them on a trolly, push them into the paint shop & start the next boat.

RFNK
08-13-2009, 05:03 AM
Really nice! I want one!! Rick

lesharo
08-15-2009, 02:19 PM
Norton Champagne is the equivalent of 3M Gold and if you want something that may be even better, try Carborundum Premier Red. If you've got Norton available; you might have Carborundum too. They might even be the same company now.

pcford
08-15-2009, 03:29 PM
Might add some information from my prep and finish guru, Kim Lazare.

Kim uses garnet paper (the cheapest grade) for doing a final grit pass because it crumbles and the grit gets smaller....never tried it myself.

lesharo
08-25-2009, 12:05 PM
About the best result I've seen for before finish coat sanding is 3M trimite 320. It doesn't cut like the 3M Gold, (the Gold 400 would be closer to the Trimite than the 320), but it leaves nicer silkier surface and I believe a higher gloss. The Gold is much more aggressive and lasts longer and is more moisture resistant though. 320 Gold throws dust like crazy (for what seems a very fine grit).

kc8pql
08-25-2009, 01:07 PM
Waterborne urethane has become my standard cabinet finish over the last 6 or 7 years. It keeps the Ohio EPA out of my shop and vastly reduces the hazardous waste record keeping I have to do. There is a warning on the can that says not to use over fillers or stains containing stearates, but nothing about sandpaper. I regularly sand between finish coats with stearate coated nofill sandpaper with no problems at all.

donald branscom
08-25-2009, 01:26 PM
Did I read somewhere not to use Stearate (Sp?) sandpaper on paint that will be painted over? It will fish-eye? I think this is the most likely cause of the problem I just had on my dinghy. Fish-eye on the first topcoat. I used Norton's Canadian-made "No-fil Adalox" to sand the undercoat. I've wet-sanded it off & recoated & it is o.k. But wet sanding is a pain. Literally. You can't tape up your fingers wet sanding & I'm bleeding from three of them. Is there a better way? Any advise will be apreciated.

You should not b sanding with your fingers.
Use a block of wood or other device. You will get a better result.
When you sand using your fingers your soft fingers will just follow the low and high spots. The low and high errors will just get lower and higher.

Candyfloss
08-25-2009, 04:46 PM
Donald, normally I would agree with you, but lapstrake is different. It's too easy to take all the paint off the edge of the overlapping plank with a block & where the strakes bend & twist around the bow the plank is effectively cupped. On a plywood boat I would hold the block at a certain angle & sand in a certain direction to overcome this, but on a lapstrake's narrow planks this is not possible & you just sand the edge of the plank off. At least that's why I abandoned my sanding block.

pcford
08-25-2009, 05:32 PM
Donald, normally I would agree with you, but lapstrake is different. It's too easy to take all the paint off the edge of the overlapping plank with a block & where the strakes bend & twist around the bow the plank is effectively cupped. On a plywood boat I would hold the block at a certain angle & sand in a certain direction to overcome this, but on a lapstrake's narrow planks this is not possible & you just sand the edge of the plank off. At least that's why I abandoned my sanding block.

A 3M soft would not work?

Candyfloss
08-26-2009, 04:51 PM
Alas Mr Ford 3M products do not jump off the shelves at you in your average Kiwi hardware store, & here in Thames our hardware store is pretty bloody average. But I fear a lack of detail may have thrown my kind correspondents off the scent. The paint I'm using is a two-pot polyurethane of local manufacture & this may be the difference.

Candyfloss
08-26-2009, 05:40 PM
Astonishing what you learn if you hang about on this Forum long enough. Today it is don't use the search function to search the Forum. It's bloody useless. Instead use Google, so I did. On the topic, but a completely different Forum:

"07-24-2003, 06:32 PM
I've had a fair amount of trouble with it (stearate sandpaper) when using polyurethane or synthetic enamels, so much so that we no longer have it in the shop. I can't trust it to perform predictably. Might be different with epoxy, and you can always clean, clean, clean. But did you get it all in that critical spot?"

So, it appears other people are having trouble with the stuff too, when used under polyurethanes, so Mr. Ford I'm off to find some 3M Gold. This used to be a goldrush town, must be some around here somewhere.