As I have read, sanding is the most boring task, but really important.
Which sanding tools have the modellers? Are you a sanding expert?
Can you then explain to us what´s the best way to sand? Using sanding blocks? Sanders?
How do you prepair your own sanding blocks? What kind of sandpaper do you usually use for the different parts?

Yes. I had a sandbox when I was four years old.

Courser grit to finer. Any straight or flat sections should be sanded with a saning block. Hand sanding without a block will round edges, leave dips and rises, and should only be done to form or follow curves.

I have small sanding blocks of 4" right up to long metal extrusions of 24", in several grits. 60grit shapes FAST and actually shapes parts. 150 grit is good for smoothing edges. 220 begins to leave a finished surface. 400 leaves a very smooth surface. 600 gets a very nice finish; and with repeated applications of a sanding filler will leave a surface ready for paint. if I'm covering a model with heat shrink I (personally) sand with 400 and stop there. Wiping with a lightly damp rag between sandings will raise the grain and clean the dust off. Let it dry and sand again.

Have a nice stable and flat work surface to sand on. Use long strokes back and forth WITH the grain. Never swirl and don't cross the grain unless you are removing lots of wood or shaping an edge. Take your time, have good lighting

Sand ribs together and not one at a time. If you do them one at a time you'll have different sizes that will mean you'll have to take more wood off to make the wing smooth when they are assembled. You can also not sand them at all until they are glued to the spars and leading/trailing edges and then sand with a 24" wide block, doing multiple ribs at once.

Hi!
I use a long (30cm) aluminium U-bar and wrap the sandpaper aound it (see picture).
For a good finnish it's vital that you have good sanding papper.
Best sanding paper on theis earth is a sanding paper from Portugal called "Indasa red line, Rhino dry plus " )
This sanding paper is soo good and will last longer than any other sanding paper I've tried in 32 years modeling that if you only have used 3M or Norton before you will be amazed...
I have used it for more than 10 years now and mostly use 180 and 240 grade and a fine 500 before putting the final layer of paint on, using Sikkens Autocryl 2 part auto laquer.

For heavy sanding the best sandpaper so far is a cloth-based paper called "Hiolit" I prefere to use grade 80. This paper is so tough that it sand 24 hour epoxy and microballon covered balsa wings with ease without loosing it's bite or brake.

What about electrical sanders like this one
http://www.tooled-up.com/artwork/Pro...0603919770.jpg

Are they used by modellers on specific areas?

I think your wood is gone too fast with those things, I always sand with a sand bar and some paper. Works fine, but it's indeed a boring thing to do.

Sanding is not boring at all if you do it right.

1. Take project under shade tree
2. Bring lawn chair
3. Bring tunes
4. Bring beer
5. Oh yeh - don't forget to bring the sandpaper

I am definitely NOT an expert.

I have used a sander like this on my models, mostly on the plywood parts. They can be pretty aggressive on balsa, so you do have to be careful if you use it there.

Also when snading larger flat surfaces, I like to use a cross hatch pattern. For example; if you are sanding a wing, take your sanding bar at about a 30 degree angle stroke to the leading/trailing edge from tip to root then come back from root to tip with the opposite 30 degree angle making a cross hatch patern. Remember to not force the sand paper onto the wood and take material in small amounts as it is a lot easier to take more off then to put it back. This technique is one I learned doing body work on my old Mustangs and the results are such that after paint no one can tell I had to do any work in that area.

After sanding is it necessary to clean the surfaces with a humid rag/cloth?

I understand, that the purpose of sanding is to obtain better results while covering. Isn´t it?

Quinoa,
Yes, you need to remove all of the dust from the wood after you sand it. The best thing to use a tack rag to remove the dust. If you don't have one you can use a damp paper towel to do the same thing.

Hope this helps

Ken

I agree! I normally use 100 grit and a block of wood, blow dust off and cover it. Like a guy at the field once told me. "Who cares what they look like. I'm here to fly and have some fun"

As a beginner, the wrinkles in the covering should cover up most of the nicks and gouges in the wood anyhow!

Now if you're plan on entering your plane in the Toledo Show, then I'd find myself a book on how the professionals do it.

Sanding
If a plane is properly put together, improper sanding of exterior surfaces will not affect flight much. However, it will greatly affect how sleek and refined the craft looks at completion. It is crucial to sand joining surfaces that will be adhered for a better bond, but superficial sanding can be done to any degree of desired perfection.

It helps to have adequate sanding tools and materials. For large surfaces, a large block sander is helpful to ensure that surfaces are flat and consistent. Often a hand planer help start off with a smooth surface. Small curves surfaces can be sanded with various hand or automatic tools, but a skilled hobbyist can often achieve the same or better results with just a piece of sandpaper. Glue joints should be smoothed out to prevent roughness showing through the plane's skin. Larger spurs or glue deposits can also be removed carfully with a hobby knife. Inspecting the plane from many angles and striving for symmetry, smoothness and consistency yields the best results.

The Permagrit sanding blocks are the best type of sander for hand sanding. They cut so much quicker than glasspaper that just a couple of strokes is often enough. This means you make a few controlled strokes and accurately cut to size.
They are expensive but you really only need 1 large sanding block.

Do these Perma Grit sanding blocks last long time? Do they have different grits?
I understand that this block is made of aluminium and the sanding surface doesn´t wear out.

Consider wearing a dust mask and standing upwind. I don't know about other people but balsa dust really irritates my nose and throat. I call the symptoms "balsa flu".

Hi

I have a permagrit sanding block and many of the coarse sanding tools, they have lasted me many years and had a lot of use, even the ones that get most use and are a bit clogged still work.

They can be declogged with paint stripper although i havn't done that yet.

Simon

Someone mentioned wearing a mask. Good idea. Balsa wood can harbor dormant mold spores of a tropical variety. Some can be lethal if they get in your lungs.

Aside from flying and building planes, I build furniture for fun. Although most furniture is made of much harder wood than balsa, the methods for sanding are very very similar. Coarse grits will shape and remove material very fast. I would not recommend using a palm sander on balsa. I fear that it will remove too much material, way too fast.
- Start with a coarse grit, work your way to finer grits. The finer the grit, the less material is removed.
- For large flat expanses, use a sanding block.
- Never go against the grain.
- Typically, I use my hand when sanding, I like the feel I get from working the wood. It allows me a more personal connection with the wood. But that is a
developed sensation.
- A sanding sealant works wonders if you want to leave a glass like surface to work with. These are commercially available.
- Between grits, wipe your surface with a tack cloth (usually cheese cloth with a sticky substance applied to it, available in the paint section of your local
hardware store), or a damp, NOT WET, cloth. This will help to remove dust. A damp cloth will raise the grain a bit, but if you
leave it sit, you can still achieve a nice surface.
- Do your sanding after your aircraft is near or in final assembly. This will allow you to make sure all your mated surfaces get sanded together and you don't
end up with erratic edges.
- Good ventilation is always a plus.

Hope this helps a bit.

I have found in tower hobbies the Great Planes Easy-Touch Bar Sander
[link]http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXK315&P=7[/link]

Does anyone have it. Any difference with the Permagrit sanding blocks?

I'm sure that it works great, and for 5 dollars US not a bad deal, but what about overseas shipping? How much for that? Do you have any local hardware stores? If so, and you're looking for something lightweight, try the aluminum U channel method Jaka shows.

Can someone explain about 'wet' sanding? I've been building for many years but always sanded everything dry. Why and on what materials do you wet sand? Do you use straight water or with something added? Do you use a special type of sandpaper?

ho2zoo,
Wet sanding is just like it says. You sand using water to carry away the material you sand off. You need to use wet-dry sandpaper so that your sandpaper doesn't come apart from the water. The material is non-porous materials like metal. Wet sanding accomplishes two things. First it makes your paper last longer as the water carries away the sanded material so the paper doesn't clog up. Secondly, it provides a better finish because the material carried away by the water doesn't "scratch" the surface you are working. You wouldn't wet sand materials like wood because the water would warp the wood. Overall, when it's used wet sanding will give you a much better finish of the material you are sanding

Ken

Wet sanding is something you never want to do with wood. Wet sanding is a method used on metal, stone, and other hard materials. Essentially what wet sanding does is use the water as a media to hold down and carry away the dust. It also has a secondary function of cleaning out the sandpaper as you go along. Wet sanding uses very fine grits, usually 600 and higher. If you were to sand with these fine grits dryly, the paper would clog up and become useless very quickly. One use for wetsanding is during the painting phase of restoring a car.

My friend restores VW Bugs and other older VW's. When it comes time paint, he will lay down a primer coat, let it dry, then wet sand to smooth out the primer coat. Secondary coats of colors, same situation, then the clear coat. He wet sands the clear coat to a get rid of any uneveness or runs in the clear coat. TO make it all smooth and even. Then he buffs the living daylights out of it to make smooth like glass.

Wet sanding can also be used on fiberglass, to keep the dust down and make the surface smooth.

Hope that this helps you out a little.

Hi!
I totally agree! You never wet sand wood...And I would say ...you never wet sand a model built of wood, even if it is covered in thin glassfiber.
The best way is to dry sand and then use thin glassfiber and epoxy (or polyester resin) and use automotive 2 part laquer and spray paint the airplane.

Then, when everything is finnished...and if you want a mirror finnish...then you wet sand the whole airplane with 2000 paper...yes you sand it! And then polish it with automotive polishing compund like "3M finess it" nr 1-2 and 3. Then you have a mirror like finnish ,better than a new car.