Sanding and Typing in Pain

[Quetzalsailor]

My usual 6 finger typing is severely impaired by today's activity. Three of the left-most fingers of my left hand are sanded through.

So, the problem is to sand out the concave interior of a certain 20' long structure that has been coated out in West's special coating hardener and 105. The coating job is not all that rough, but the inevitable (to me) runs and bubbles need to be removed along with the amine blush. I started by using a small scraper to knock off the dits and flatten the drips. I began sanding with 220 grit garnet paper but the stuff fills quickly with the sticky blush. I switched over to 220 grit wet-or-dry and production sped up satisfactorily. However, a mere 8 hours of work today (and several previous), in 90 deg shade and high humidity, removed enough skin to cause me to cry 'uncle', shower, and commence drinking. The job is 2-3 hours shy of half done. (My right hand was partially de-nerved and muscles atrophied about 20 years ago, so there is no corresponding damage (or ability to simply switch)).

At the very least, I need a suitable way to hold wet sandpaper with decent feel. I have the usual rubber sanding blocks and cloth-wrapped wood blocks but they do not have the shape or flexibility to get into the places this structure presents. Rubber gloves? Knit gloves?

[Rachel]

I began sanding with 220 grit garnet paper but the stuff fills quickly with the sticky blush.

I'm not really answering your question, but on the paper clogging with blush, how about sluicing down the piece with water and a Scotch-Brite pad first, to get rid of the blush. Not that your sandpaper might not still clog, but at least it would be with epoxy and not blush (also, I think you can "grind" the blush contamination into the epoxy if you don't remove it before sanding).

I feel for you on the weather. I just laid on a coat of varnish and it went on like paste. Ugh. Heat and humidity, go away!! Plus, who wants to do anything but sip icy-cold mint juleps from frosted glasses?

Rachel

PS: Would some kind of sponge work for a backing? I can't quite visualize what you are doing.

[Quetzalsailor]

R, I'm using the 220 wet-or-dry wet, so the grit stays clean and the blush is carried away with the 'dust'. Rinsing the paper in a bucket, wiping the work with a damp towel and changing the water periodically. Rinsing the blood.

I'll try your sanding sponge idea - I have some of those 3-M grit-faced sanding sponges - , but wrapped with the 220 w-o-d.

The game at hand is to prepare the interior of FD US 29 for several coats of marine varnish. Soon, I hope, install hardware that will be an inconvenient reach after the deck goes on.

Before starting sanding out the epoxy.

On the right is the same boat in about 1957 on Biscayne Bay.

[Tom Young]

I feel your pain Doug. While I spend much of my time working with my hands building and restoring houses, I rarely if ever hurt my hands. The work is never that demanding. But come springtime and working on the boat, is a different matter. I was convinced this spring I'd taken a real physical downturn, a sudden onset of arthritis and other ailments. Plus various sudden new open wounds caused by honing off skin were very painful this year.



But you made me realize sitting here, I feel fine right now. My hands look and feel fine as I'm engaged in restoring a a big old house down the street.

My boat is very hard on my hands.

I've found only one thing that helps. Gloves. Go to the hardware or building supply store and begin buying gloves. Buy a pair every time you go in. This is important. Put the extra pair in your car, garage, kitchen drawer. Get another pair, and another.

Buy types you've never tried. I wore out a pair or two of a rubber and cloth combination in some boat sanding this spring.

Treat them like reading glasses, have plenty around. Sure you can read without them with the book on the table in front of you, but,....

[Quetzalsailor]

Thanks, Tom. I, too, have found that boats are harder on me than houses...usually. One of my FD took hunks out of me whenever I sailed it; it also took a hunk out of me when I walked past it on its trailer in the dead of winter! I also find it difficult to use gloves - a not-so-rare act of stupidity.

The worst injury that I've done to my hands, if I do not count the de-nervation from stapling, or hack saw slices, or the table saw nick, or falling on an upstanding nail, or the three-fingertip chisel slice, or the architect's favorite: excision of fingertips with an Exacto while model-making, is removing fingertip skin with mortar and CMU. The CMU (cinder blocks to most of us) abrade, and the caustic limes and cements in mortar dissolve skin. Masons, of course, use gloves.

I tried sanding last night using a surgical glove on the abraded hand. Amazingly enough, it lasted for the hour and a half and was unharmed. Pretty good feel but not so good control since one's fingers slide inside the glove. Of course, all of us who use epoxy have surgical/exam gloves; my only problem is finding the xx-tra large size.

[The Froon]

Doug, I have had my fair share of detail sanding (with just the fingers and paper)...I have found that taping up my top two knuckles on the thumb, pointer, index, and ring finger seemed to work well.

Happy sanding!

[bigd14]

Oh, I feel your pain! Just a couple weeks ago I sanded so much barehanded that I sanded about a dozen pinholes into one of my fingers. It looked so weird that I tried to take a photo of them but it didn't turn out too good. Here it is, anyway.



There once was a time when I though that working on houses was difficult but then I started this boat project. A little caulk and trim, and several coats of paint covers a multitude of sins in a house. Not so with a boat!

[Zach]

Heres how I do it...

Take a piece of blue styrofoam dow board, and cut it to just smaller in width than a piece of sticky inline paper. Take a piece of sticky paper, stick it to the radius where the fillet is good... and machine the foam block to that shape.

9-10 inch long blocks are about as long as you can hold on to. It is optional if you carve out finger divots in the styrofoam. Sanding wise, your thumb goes away from the fillet... and little fingers are closest.

Take the sandpaper block and work in to the fillet on a 45-75 degree to the fillet. Never sand a fillet inline to its length, as you carve a divot on each of the flat surfaces to each side. Work in from both surfaces... The foam is soft enough to conform to the flat surfaces, and work in to radius.

Thats the easiest way to sand them.

For stuff that is painted:

Sand the flat surfaces to each side of the fillet first so its flat and smooth. That means longboarded and in primer.... Your fillet follows whatever the surfaces is doing, so if you have swoops in the surface, it'll show in the fillet. It'd be like taping a poorly done sheetrock corner... ends up sticking out like a sore thumb.

If you were painting the inside of the hull you would rough sand the hard stuff to give some tooth... then come back with a trowelable fairing compound. Awlgrip Awlfair... Alexseal's grey... system 3's silver tip... or any of the others that taste the same. What you'd do to ease your sanding, is to pull a fillet with a home made plastic tongue depressor on top of the harder surface. Cut the round end to the diameter you want and pull it all evenly.

Now go back and sand with the styrofoam block. While it may feel like a never ending sanding project, trying to hand sand epoxy or fiberglass corners is working way to hard. Get some softer materials, even if its just a high build primer, or sprayable/rollable fairing compound. I use the little Whizz hotdog rollers to apply primers in detail areas, they don't put down a lot of material, but they don't have a lot of roller stipple either.

Good luck! And remember when you pick up something hot in the kitchen for the next couple days... your callouses are gone. Grin.

Zach

[Rachel]

Zack,

These look like some great tips! But... I'm not sure I'm totally visualizing a couple of them.

For the first one, where you are making a foam sanding block, are you saying you take PSA sandpaper and stick it grit side out to the fillet you will be sanding? And then you "sand" with the foam block so that that paper shapes the block? Then I suppose you toss that piece of paper and go on to use PSA sandpaper on the block normally.

For the second tips for painting... okay, I'm pretty much confused :blush: I do understand what you're saying about not sanding the length of the fillet due to making a groove either side of it (really? never? not even at the end?), but I got a bit lost on the primer, etc. part. But I can tell there is some great info there once I understand it. Would you mind expanding, or maybe explaining it slightly differently?

Thanks,
Rachel

[Zach]

Rachel... you've got the first one.

As far as the second part goes...

Sanding with your fingers in the fillet changes the shape along its length. If you sand along the length, you have a depression where the fillet is, and where your fingers ride. If you have a smooth block, shaped to finished product, and you work in at an angle... you sand both surfaces, the deck and wall, and end up with no ridges that show under high gloss light. It would be the same as sanding the outside of a curve in straight lines up and down it... you score in grooves.

Make the finished fillet size, larger than the fillet you laid up when you were glassing... or larger than the current hard to sand fillet.

I suggest that no one try to hand sand raw fiberglass, gelcoat, or cabosil thickened epoxy into a finished fillet. Pull a putty fillet on top, that is easy to sand.

Awlgrip's Awlfair is a trowelable two part epoxy putty that mixes 1:1. It's probably the most used putty around these parts... it's been on the market since the mid 90's and does a fantastic job. It is non-blushing, and sands very easily. Alexseals taste the same. System 3's silver tip is very nice stuff to work with, and will let you sand again 3 hours after you put it down. It is a lot harder than the other two, particularly in the sun. It spreads so much easier. I find myself using it inside for doing rough fairing... then coming with primer and awlfair on top.

What you will do, is start with the raw fiberglass or epoxy coated wood. Scuff it off with 80 grit or thereabouts and pull an initial layer that gets things close to being flat. You will longboard all the way in to the corner, using 40 grit to rough in the surface. From there you will either spray or roll a layer of awlgrip 545 epoxy primer over the surface so it just covers. With that done, you will take either food coloring and denatured alcohol and wipe the surface to change the color to green or red (they show best) or black spray paint in a light dusting. You want the spray to land as an almost dry mist.

From here you will longboard with 40 grit again. The low spots will be shown first by the remains of the food coloring, or spray paint guide coat. With that done, you'll go get a sizeable trowel if the surface is flat... a 1 to 2 foot wide sheet rock knife or trowel works well. Apply the putty to the low spot with a 6 inch plastic spreader, all around the low spot leaving it mounded up... then pull across it with the larger trowel. if you try to load the trowel first and spread it, it doesn't work very well.

With that done, you will let it kick off. Come back and sand it with a long board at 40 grit to knock off the high spots or trowel marks. Roll or spray awlquick (yellow) and let it offgas for a bit. Either hit it with a light coat of 545 while you have the gun out... or if you are rolling, wait for it to set up and go back with a your guide coat.

Sand again with 40 grit on your long board. If you are rolling, you have to take off the roller stipple. If you are spraying, just take a light touch and pass across everything.

Now roll or spray a coat of high build primer. D6001... brown stuff. Spray 3 or 4 coats, roll 2. When this sets up... long board it with 80 grit.

After that shoot a coat of 545.

You've now got something you can break out the random orbital and crank up to 220-320. Some shops around here will hand sand all the way to 320. That leaves no machining marks or anything else... and a mirror surface. Depends what you are after, I aim for attainable perfection... and tend not to like sanding very much anyway.

Now is when you pull the fillets in the corners and catch them up to the rest of the job. If you have big fillets already there, then sanding down to them doesn't work very well. You end up scoring lines in them... So, leave the finished fillets for last.

Use a fillet size that is bigger than normal. Not a popsicle. Not a 1/2 inch. Go for something the radius of a golf ball, or a light bulb. You want the fillet stick to ride on the smooth surface of both the deck and the wall. Otherwise you end up riding on the structural fillet, or any lumps down in the corner.

As far as pulling the fillet goes, you'll have to do it twice. Once will get the majority in place. You'll sand lightly to knock down the high spots with 80+ grit with your foam block. From there you will pull it again with the same fillet stick. This will fill in the pin holes and ripples left from the first go round.

When that sets up, sand lightly. Roll 545 on the length of the fillet... sand a bit with 80-120 till you see if you have any lows. Then roll a little awlquick to cover any low spots or the last of the pin holes. Sand... then spray the whole mess with 545 and call it quits.

Sounds like a lot of steps, but it goes pretty quickly. You will want to pull putty in the mornings and evenings. Do your sanding work first thing and paint. The stuff doesn't blush, and has a decent recoat time... so sanding in to the lows isn't really required. Summer days in direct sun you can get a lot done.

As far as long boards go... you can't pick at a high spot and expect good results. You need to move the board a foot or two at each move, and make sure you don't stop at the same point. When your high points are as close together as you can start pulling your trowel... sand just a bit further, and then call it quits. 40 grit sounds like its extreme... but I am talking about new construction or big repairs where you have no smooth gelcoat to start with... or if the quality wasn't there to begin with.

For sanding boards, you want as big as you can get for the surface you are working on. You want to grind the highs down, evenly and have something large enough to span a lot of distance. 3m makes fairing boards that are 4 1/2 inches wide by 30 inches wide. You will sweat... but you end up with a job that is straight. A 16 inch board that is 2 3/4 wide don't span the initial hills and valleys on new construction. It can be done... but you have to start in a corner, and work out, otherwise you end up with low spots in the work. They are for stuff the size of a car hood...

As far as sandpaper goes, I use a lot of sungold abrasives stick ons in 40 and 80 grit zicronium for my 16 inch boards. (I have a few different shapes and sizes to keep hand fatigue down.) The 3m fairing boards are velcro. Mirca's paper for them is insanely good stuff... rave reviews from me... Lately I have been using velcro on the hutchins pneumatic inlines as they seem to last longer, clog less, and give a flatter finish than the sticky pads. With any and all long board, you push them canted at an angle. Pretty much whatever is comfortable to you. For me i I cant the board around 10:00 to 4:00 or 2:00 to 8:00 depending on direction. For the initial passes, you start with a guide coat and then walk down the length of the boat, or cabin side from one end to the other without the board leaving the surface... until you see the lows, then pull them with putty, otherwise you'll end up sanding yourself in circles. Particularly with a short long board...

Speaking of sanding corners... For sanding outside corners, like the corners of a cabin you want to sand on 45's with the board up and down. Top right, down to bottom left, top left, down to bottom right. Working down an inch or two for every pass. Get to the bottom... reverse. Sand out into the flat land to each side by 3 or 4 inches... and keep the board inline to the corners length. Works for stems, and curved transom corners too. Stiff boards span from high spot to high spot... best for straight corners.

Hope that helps explain a bit more...

Zach

[Rachel]

Zach,

Wow, thank you! That was very informative and understandable. Some good concepts and also specifics - great combination. Thanks for taking the time.

Rachel

[Quetzalsailor]

And that, ladies and gentlemen, is what this forum excels at. There's always someone who's done the same job better, and can tell the rest of us about it. Thanks, Zach. And Tim, of course.

If it weren't 95 and airless, we'd be down for the week on Quetzal. Oh the misery of not even cooling off at night. We gave it up, brought ourselves and all the food home.

And, it might well be tooo darned hot to wetsand the FD in the barn.

[Quetzalsailor]

I finished sanding out the boat and have applied the first of (min) 4 coats of Pettit Flagship 2015.

I used ordinary dust-free exam gloves on my strong hand and got maybe 2 hours out of each glove.

I found that the Wetordry 220 would last longer cut into 1/8ths, means that the piece in your hand is folded only once and never grit-to-grit.

I took Zach's idea and made a single spruce 'finger', approx 8" x 5/8" x 5/8" ground to a long gentle curve on part of one face; wrap the 1/8 sheet around it longways and hold it with one hand's finger while sanding with the other hand. The curved end served to ensure that a reasonable area (fingertip size) would be in contact with the work without having to be slavish about what angle the 'finger' was being stroked at. The spruce is soft enough so that I did not bother with a cloth pad.

Between 16 and 20 hours to sand the epoxy and 2 1/2 hours to varnish. I sincerely hope the varnish will sand out more quickly; the 'dits' and drips are much smaller. I bought the Despot's 'best' brushes and used the 2 1/2" angled one and a 2" foam applicator to get under the frames.

I got pretty decent results, I think, but not anywhere as good as I want the last coat. There's plenty of dust in the barn with no possibility of getting it clean enough, no possiblity of tenting the work in plastic (I'd suffocate in heat and fumes for one, and there's no room). It's also hard to keep a wet edge starting on one side, going to the other end and coming back on the other side; hard enough keeping a wet edge on one side, varnishing in 20" or so sections from centerline to sheer.

About that Pettit varnish; it's $130 at West Marine. WM has a price beater guarantee. Both Defender and Jamestown have the stuff for $97-100 w/delivery, so I should/will be getting a refund, so says their customer service guy.

As for sanding outside corners, if they're relatively sharp, I'm careful to avoid sanding them at all until last. It's wonderfully easy to sand through or to end up with a much thinner coating on a vulnerable place. I sand the faces, sneaking up to the corner, and then hit the corner with one or two swipes. It is important to have something of a radius on a corner, of course. If it's a gentle large radius then it's important to work out a stroke, such as Zach's, to avoid sanding in flat spots. I try to do as my grandfather, a USN Captain, taught me when I was about 6 (who would argue with a Captain?): Using a flat tool, like a file or sanding block, start with the leading edge, working across the curve, stroke and sweep your hand down, finishing the stroke with the heel of the tool. This means that the tool is never touching the work in one place. The other stroke I use is to do circular patterns working along the curve.

[Zach]

Quetzal,

That is one beautiful boat. Nice work!

Zach