900 series kits Silly Question

[joecrouse]

Any advice on sanding them without breaking them. Ive tried a sanding block both big and little and really fine grit (300 grit) and they just come apart. Even sanding them slow seems to just pull them apart.

Do you folks just replace the 1/32th of an inch parts or do you make thin 1/32 sticks.

[Wildpig]

Joe, it's mostly about technique and patience. I'm not sure exactly how you are going about it, so I"ll just 'splain' what I do.
The die-cut sheets, I sand starting with 220 grit. This removes the balsa quickly. Then finish with 400 grit. I sand the whole sheet, not the individual parts. Sanding each part alone can cause them to break, easily.
Sand in one direction. Back and forth usually cracks parts.
The individual stringers,1/16x1/16 inch, i sand with a block of 320 or 400 grit. Pulling the block down the stringer in one direction. The sanding block I use most, is 3/4"high and 1" wide by 3" long. I don't think the size is too critical, it's just what fits your hand the best. Again, patience, really helps. Lots of gentle strokes with the sander. Bearing down will usually cause problems. Does this help? Or does it sound like a silly answer?

[Pauli72]

Wildpig is absolutely right. It's just a matter of having the right light touch, and all the techniques he listed are exactly correct.

One thing you may also want to give a try is a Soft sanding block to wrap your sandpaper onto. (foam rubber or similar spongey material). 4in x 2in x 3/4 inches. This has really helped me out.

[joecrouse]

I may not have made myself clear

The parts them selves sand well enough and hold together remarkably well when removed from the individual flats.

Its the assemblies specifically the tail and horizontal stabilizer where the stringers are 1/16th and the flat pieces are 1/32 or so. Trying to sand everything down to somewhat even causes the stringers to either roll on the board and twist the glue joints into breaking.

[Steve Blanchard]

Hi Joe,

If I hear you right, you are using 1/32 parts around the edges of the tail surfaces and 1/16 square stock for the inside sticks. If so, then Guillow is not supplying the correct stock for the die cut pieces or vice-versa. You should have the same size (thickness) sticks as the die cut pieces. All you should need to do when sanding the tail pieces after assembly is minor clean up of joints if necessary, and rounding of the outer edges all the way round the outer shape of each assembled tail piece. I suggest replacing most of the wood in these kits anyway, but if you want to use the kit wood, try to keep some extra stock on hand in different sizes to better match the die cut pieces for thickness. If you do get uneven areas and you want to thin down the assembled piece, it is best to put the piece on a flat piece of sandpaper, preferably glued down to a board, and then with a good size (4" x 2" x 1" thick) sanding block you gently sand the whole piece. The sand paper on the board will hold it still while the sandpaper on the block will thin the pieces to where you want them. Go slowly and check your progress often. I hope this helps.

Steve

[kittyfritters]

Yes, the sheet wood in the 900 series kits is 1/20", and unlike many die cut Guillow's kits they are quite light and can be made to fly quite well with little extra effort. Although, it would be interesting to see how one would fly if made of 1/32" wood...

[sawingman]

Take a look at this technique used by Phugoid illustrated in the Cessna 180 Group Build. It has worked well for me!
viewtopic.php?f=2&t=2215&hilit=group+build&start=210
(In case the link doesn't work, it was posted Nov 13, 2011, 6:09 am)
Good luck.

[Wildpig]

Very good tutorial with the 180 build. One other thing I do is notch D2 and the trailing edge pieces about 1/16" and cut the 1/16 stringer stock longer to go in the notch. This provides more glue contact area. This also reduces the "rolling" problem joecrouse was describing.

[ADW 123]

you will notice the tail parts for this series have die cut parts that are 1/20" thick and you use stock strips that are 1/16" sq. When i made my last cesna, i just made the 1/20" parts into 1/16" by cutting new ones. this way, you arent sanding all those strips which is a pain. they tend to break apart easily this way.

[joecrouse]

yea thats what I did just said the heck with it and re built them at 1/6th.