Sandpaper

[Justin P.]

Hi All, 

 

Apologies if this topic is covered elsewhere, I think I did a pretty good search ahead of starting this thread - but you never know. 

 

Ive done quite a lot experimenting with different brands/types of sandpaper over the years and Im curious, what's your favorite and why?   Whats your go-to grit sequence for finishing parts?   Ive lately been making sticks with a 400, 600, 800, 1200 sequence using wet/dry paper.   This stuff seems to clog quickly, but is far easier to use on custom sticks than the higher quality brands.    

 

Whats your experience?

[mtaylor]

I do the same as you... make stick, glue some sandpaper down.  Also the same grits.   The other thing for sanding I use a lot is those disposable finger nail files.  They're flexible and come in many grits.

[CPDDET]

Manicurists buffing blocks come in handy as well. 

[druxey]

Wet and dry paper is used for metal, not wood. This, and the fact you are using extremely fine grades is why you are getting clogging. Garnet, emery, aluminum oxide and silicon carbide are used on wood. See:

 

https://www.empireabrasives.com/blog/sandpaper-grit/

 

Usually, for wood, 400-grit is as fine as you need to go.

[Gaetan Bordeleau]

On my drum sander, I use #80 grit, sands in the grain direction and gets much better results than we would expect. The paper comes in rolls and last for months.

As for sand paper, Diablo makes excellent saw blades and I discovered few months ago, that they are making a higher quality of sand paper, also red in color. They also make sanding paper for orbital sander of a very good quality which last longer than any other brand I tried.

 

Wood is not made for the finest sanding paper, metal and paints are.

[glbarlow]

Other than fairing all I use is 150, 220, 320, & 400. I have never finished anything beyond 400 grit. I really like Soft Sanders with their adhesive paper, foam sanding sticks I get on Amazon and more adhesive sandpaper on small wood block I cut, 1 ¼ and 1 ¾ square by ¼ thick plus loose paper in those 4 grades. I have a tray on my bench filled with all this stuff. 

[Jaager]

For surfaces that meet and are PVA bonded, 220 grit is right at the edge of not leaving a surface rough enough for the polymer chains to grip.  I am sort of OCD about 220 grit  and that fine  is pushing it, I think, but my structures hold.

From what I read, open coat aluminum oxide is the gold standard for wood.

[mikegr]

 For wood I use dry type from 80 to 240 grit. For hull sanding and other tasks I use sanding sponges I like their grip and the shape.

I also use rectangle ones which I replace the paper once it get worn. I glue it with PVA. Sometimes I combine grit. One flat side 240 grit, other with 120 etc...

Edited October 9, 2021 by mikegr

[Justin P.]

Ive used/tried many of suggestions above.   For whatever reason every time I use something with a soft structure like the emery sticks or pads, sponges, I end up rounding over parts.   I pretty much stick to hard shapes now, but take the point about going any higher than 400.   I have enjoyed using an aluminum oxide brand called Gator, but their sheets come with that proprietary backing intended for their sanding tools which cant be removed.   This makes it difficult to get a purely flat surface.  

 

 

[Snug Harbor Johnny]

  When hull fairing is achieved (or that of other surfaces), have you considered using a scraper?  Cabinetry scrapers are too large for most model making, but fashioning mini scrapers using short pieces of (de-toothed) hack saw blade can be used to have a finish largely free of 'fuzzines' (unless the wood is too soft on its own).

[stuglo]

38 minutes ago, Snug Harbor Johnny said:

  When hull fairing is achieved (or that of other surfaces), have you considered using a scraper?  Cabinetry scrapers are too large for most model making, but fashioning mini scrapers using short pieces of (de-toothed) hack saw blade can be used to have a finish largely free of 'fuzzines' (unless the wood is too soft on its own).

Single edge razor blade or 22/24 scalpel blades

[CPDDET]

Gluing sandpaper to rigid pieces of wood should solve the rounding off issues. I use several different sizes of wood for this, everything from popsicle sticks to 1 X 1 X 6 blocks for faring. Just purchasing sheets of sandpaper in various grits and use spray adhesive to make your own sanding sticks. 

 

 

Edited October 10, 2021 by CPDDET
change

[vaddoc]

Try 3M 618 sand paper. Amazing stuff, I only use this for many years now. It is silicon carbide (not aluminum oxide), has some anticlog technology that works very well and it is very robust. It is not cheap and needs a bit of googling. Typical 3M high quality.

120 removes wood in a controlled way, 180, 240, 320 and 400 leave the wood so smooth that it reflects light.

I cut sheets of all grades into thin strips and use them with a solid flat backing, or sometimes a flexible one - as needed

[Jaager]

Following a suggestion from Don Vardas : 

 

"For the time being, use a heavy grit paper (80 is about the best) for your initial "rough" sand and finish it off with lighter grits to 240 grit. If you Contact Cement the paper to a cork block it makes it a lot easier too. Buy an extra cork block and shape a "half-round" into it to do inside curves."

 

I bought a cork bock sold for Yoga.  Using my bandsaw  I cut a variety of small blocks curved and angled.  But rather than the aggressive and messy contact cement, I use rubber cement. It hold well enough as long as both surfaces are  coated and allowed to dry before mounting the paper.  This does preclude the use of Norton 7X or 10X  most commonly found in big box hardware shops.  Rubber cement does not like the no skid coating on the back.

[Bob Cleek]

18 minutes ago, Jaager said:

I use rubber cement. It hold well enough as long as both surfaces are  coated and allowed to dry before mounting the paper. 

"There's an app for that." Stock item at auto body and fender supply houses. Expensive, but a little goes a long way and you'll make up the difference in sandpaper savings.

 

 

Additionally, particularly with power driven abrasive disks and belts, the regular use of a crepe rubber cleaning stick will extend the life of the abrasive sheet considerably. They are cheap and last forever. POWERTEC 71002 Abrasive Cleaning Stick for Sanding Belts & Discs | Natural Rubber Eraser - Woodworking Shop Tools for Sanding Perfection - Vacuum And Dust Collector Accessories - Amazon.com

 

 

 

Edited October 10, 2021 by Bob Cleek

[Chazz]

I use sandpaper glued to a backing for much of my shaping of small parts which does not work out with knives or saws.  (However they do make less of a mess, as does scraping.)   I have all sizes from flat sticks an inch by a quarter inch by a foot long to small ones  a half inch by an eighth, and dowels sized to the curve they're to work on.

 

I've never found a need for fancy glues to fix the sandpaper...I just use Elmer's Glue Pen,  very water soluble and easy to use.  Ir's like the old mucilage from grade school, sticky tan like honey.  It comes in an applicator container and keeps forever,

It dries in a half hour or so, new paper can be applied right over the old for some time and peeled off by wetting the stick.

 

I've found that by using a backing stick much longer than the work, the sanding work results are more parallel to the worktable.

.

[wefalck]

For fine finishes, particularly after having applied sanding filler, I also use steel-wool of various grades. It gives an nice satin finish - but make sure to remove also the little steel splinters !

[stuglo]

3 hours ago, wefalck said:

For fine finishes, particularly after having applied sanding filler, I also use steel-wool of various grades. It gives an nice satin finish - but make sure to remove also the little steel splinters !

On larger surfaces, such as hulls and decks, I apply tung oil with the steel wool, and then wipe off any excess. 

[druxey]

If you must use wire wool, use bronze not steel for the reasons given above. However, it's hard to find these days.

[Justin P.]

18 hours ago, SpyGlass said:

I go for a scraper for most flat or convex surface - simply a "snap off" blade off

Are you adding a burr as you would with a traditional cabinet scraper or just using the blade as is?

[wefalck]

I am using razor-blades, the ones with a reenforced back. And I am using them as they come. Seems to leave smooth, flat surfaces.

[stuglo]

13 hours ago, druxey said:

If you must use wire wool, use bronze not steel for the reasons given above. However, it's hard to find these days.

Never had this problem. I use the  kitchen variety on harder woods such of walnut. Even against the skin it doesn't scratch. Of course, the wood is already smooth and minimal pressure is applied.