How do I make the edges smooth?

[wolfcoast]

I've been lurking for a while trying to learn before I posted anything. Currently I've been trying to make a few templates out of plywood to make my own bodies. I made one pattern from a strat style guitar I own and one of a Mockingbird and a Jem style guitar (from cad drawings I found on the net).

All 3 templates were cut from 1/2 plywood on a band saw and then sanded using a drum sander in a drill press. While using the drum sander, I think I stayed in some areas too long making small depressions. I seem to be having a hard time making all the curved surfaces smooth along the edge of the template. In most cases the slight "bumps" are real hard to see with the eye but can be easily felt running a finger along the edge. It seems like no matter how much I sand, I can't get a perfect smooth surface.

Is it just a matter of patience or is there a trick to it I'm missing. I don't want to make a body from any of these templates until they are as perfect as I can get them.

[guitar_ed]

Hi Wolfcoast,

I think that you will find it is a question of both patience and practice. Also, don't push the wood against the sander very hard. More like a light kiss.

Guitar Ed

[GREGMW]

I found if you keep the timber moving along and dont push it into the drum should help

[wolfcoast]

Well that definitely would explain part of it.. It has been a while since I actually did the work since I'm in the Navy and just got back from being at sea.. I did the majority of work on them before I left. But I distinctly remember pushing rather firmly against the drum sander so that probably is the cause. I'll have to keep that in mind next time I use the drum sander.

[Drak]

Most of my templates are around 1/4" thick, it makes it easier to sand and keep an eye on things I think. When I tried to make a template out of 1/2" material, I noticed it was more difficult to get it perfect also.

Now, having said that, it would be nicer I guess to have 1/2" templates, but I do fine with 1/4".

PS, good on you for holding out for perfection on your templates, it's the only way to go. Your patience will pay off when you finally have a perfect template, you will be glad you waited and did it right.

I think it would be kinda hard using a drum sander, as there is very very little surface contacting the sander at any given time. A belt sander presents much more surface to the sander, I think it's much easier, but ya gotta use what ya got on hand. A drum sander is GREAT for doing the inside of the horns, but would suck I think for the rest of it. Just get 'very close' and then do the rest by hand.

I think the key is to slowly work toward your line, roll the template around very evenly. I never stop in any one place unless it's when I'm just starting out and getting rid of some obvious fluff extra, but when I start getting very close to the line, it all becomes smoother and it 'flows' around the sander very smoothly with little pressure. But I think that would be much harder to do with a drum sander.

You may wind up having to do 'all' your 'final' sanding by hand with a block (scrap piece of wood) sander...

But in the end, you'll always have to do some hand sanding to get it perfect, and running your fingers around the edges like you're doing is the -perfect- final judge, your finger tips will let you know when you've finally nailed it.

BTW, I also lacquer my templates with just a coat or three to keep them smooth and to keep them from warping. Although I shoot mine with a gun, any clear spray-bomb would work also.

You do have your centerline clearly marked on your templates, yes? Very important.