Official Luthiers Forum!
http://www-.luthiersforum.com/forum/

Drum sander advice
http://www-.luthiersforum.com/forum/viewtopic.php?f=10102&t=7502		 Page 1 of 1
Author:  vandenboom [ Thu Jul 13, 2006 12:50 pm ]
Post subject: 
I am close to finishing my first guitar and have lots of ideas about what I plan to do differently for the next one. One goal is to not have to plane by hand the top, back and sides - time consuming and I am not real good at it. So I have been checking out drum sanders. 20" width will do the job nicely but the price is prohibitive. 10" price is within reach I but am unsure whether either of the following 2 approaches are possible using a 10" sander which gives 20" coverage by doing 2 passes.

Approach 1. If I get the 2 halves down to the desired thickness first before joining, can I then join them reliably even though they are very thin. The couple of books I have been working with certainly don't use this approach. If you think this is risky, what would you consider a minimum thickness for joining?

Approach 2. If I join the plates first (say at 5mm), use safe-T-planer to get the thickness down a bit, can I use the drum sander in 2 passes? The concern here is the pass that goes against the grain - will it tear out or cause other damage that can't be removed by scraping?

If neither of these approaches are a goer, I will need to look more seriously at making my own 20".
Looking forward to your thoughts and experience on this.
Frank
Author:  Jim Watts [ Thu Jul 13, 2006 1:18 pm ]
Post subject: 
Frank,
Welcome to the OLF if you haven't been already.
For me approach 1 is definetly out. There no way I would get a dead flat joint. wood sands better across the grain anyway. I have a Delta sander that's wide enough and only finish sand along the grain.
Making a 20 inch sander is a great option. I think you'd be happier with it than a 10 inch sander.
Author:  Alain Desforges [ Thu Jul 13, 2006 1:20 pm ]
Post subject: 
Frank, those are very good questions. Now I'll first state that my experience is very limited as I am just completing my second guitar. So please take that into consideration with my advice, but here it goes.

In the last year (maybe a bit more) that I've been building, I've spent a ton of money on things I really didn't need. It's hard to know exactly how you want to approach building, and it's not easy seeing ahead of time all the pertinent tools you'll want/need.

That being said, I can honestly say that if I had it all do to over again, the first, and I do mean the VERY FIRST tool that I would buy, is a good capacity drum sander... I can't recall all the times that I wished for one. Thicknessing plates, finger boards, bridge blanks, end-grafts, braces, brige patches and on and on... Think about it. How many times do you have to thickness stock while building a guitar?

As for thicknessing and joining after. I think the reservation against this is that you might find it harder to put pressure on thin plates while joining them and that they will tend to warp/move more than thicker stock. Some will argue that the fit should be perfect and that hardly any pressure is needed anyways... This is true too. I don't really see why a set of plates that 'candle' perfectly should need to be very thick to be joined...

But again, with a good thickness sander, you can join thick, pass it under the drums a few times and you have a nice uniform plate. The finish can be very good if you have a double roller machine.

By the way, I don't know how much of a 'machine head' you are, but some very gifted/renowned builder have successfully built their own thickness sanders at a fraction of the cost. If you're a gifted jig-master, this might be a viable alternative. Just a thought...

Hope this helps.

Cheers,

Alain

Alain Desforges38911.934525463
Author:  letseatpaste [ Thu Jul 13, 2006 1:20 pm ]
Post subject: 
I have the Performax 10-20 sander and it works fine. I join the plates first and then run them through twice. If you have space and proper power requirements, save up and get something like the Performax 16-32 or the Delta 18" or something. That said, I'm happy enough with the 10-20 that I'm not actively looking to replace it.

I tried the Saf-T-planer, but I just couldn't get it to work well, though I know others swear by it. It seems the guys that use it don't usually need a drum sander in addition to it.

It's been said before but it bears repeating... Remember to budget for a decent dust collector (not a shop vac).
Author:  Phil Marino [ Thu Jul 13, 2006 2:24 pm ]
Post subject: 
[QUOTE=vandenboom]

Approach 2. If I join the plates first (say at 5mm), use safe-T-planer to get the thickness down a bit, can I use the drum sander in 2 passes? The concern here is the pass that goes against the grain - will it tear out or cause other damage that can't be removed by scraping?


Frank[/QUOTE]

When you say "against the grain" you're talking about the preferred planing (or sanding) direction caused by runout in the wood, right?

I could be wrong, but it seems to me that if there is runout in the top ( or back) , that after bookmatching, the grain on one side will be the opposite as on the other ( for example, one side up, one down). That's why sometimes, one side of a top looks darker than the other.

So - as long as you sand the first side of the completed top "with the grain", when you turn it around to sand the other side, it will also be with the grain.

Phil
Author:  Serge Poirier [ Thu Jul 13, 2006 3:31 pm ]
Post subject: 
Hi Frank, welcome to the OLF!

I'm also a newb at building guitars and working on no 2 right now and you'll be able to discard what i have to say in a second but let me just say this, one of the first jigs i made to help me pronto and save a few bucks was my 18" drum sander, you have a lot of info on the net to help you build one, you can either have a free plan or buy one, i think the name that comes to mind for the free plan is Dominic P, you might want to copy and paste this link in your browser! Check it out!

http://www.rockslide.org/drum%20sander.html


Here's apic of mine after gathering some ideas out there



It does a great job and i'm proud it only cost me about $200 in parts!

Serge
Author:  Jim Watts [ Thu Jul 13, 2006 4:27 pm ]
Post subject: 
When Frank said "agaist the grain" I assumed he meant perpendicular to it. Which is what I was referring to in my post. I might be wrong though.
And Phil is right about the runout in the top when book matched.
Author:  Colin S [ Thu Jul 13, 2006 8:06 pm ]
Post subject: 
I've owned both the 10-20 and the 16-32 and both will do the job just fine, I found I could work more accurately with the 10-20, I think due to the shorter length of the cantilever.

My approach was to thickness top and back plates to 3.5mm before joining, after joining cut out to rough shape and pass through diagonally to thickness. So, approach 2 would seem to be best though 5mm seems rather thick. Once you've had a 10-20 the next step really should be a wide belt sander.

I went from the 10-20 to the 16-32 and almost instantly wished I'd stayed with the 10-20. Remember that in the UK they are nearly twice the price you pay in America! I've sold them both now and have gone back to the Wagner an hand planes as I prefer the more hands on approach to building.

I would have kept and still be using my 10-20, if the upgrade bug hadn't got to me. As Hesh says, those that have them, love them to bits.

Colin
Author:  Colby Horton [ Fri Jul 14, 2006 1:42 am ]
Post subject: 
My Performax 10-20 just came yesterday. I ran some wood through it last night. So far it seems to be doing a great job. I highly recommend it. $499.99 from woodcraft, free shipping I think until the end of this month.
Author:  Robbie O'Brien [ Fri Jul 14, 2006 2:00 am ]
Post subject: 
My 2 cents worth...

Even if you have a drum sander you still can benefit tremendously from the safety planer. If you only try to thickness using the drum sander you will go through a bunch of belts in a hurry and create a lot of dust. You still must scrape and sand the pieces anyway before finishing.
If you are on a budget or don;t have much shop space just use the safety planer and then sand and scrape to remove the marks and you are ready to go.
Author:  Colin S [ Fri Jul 14, 2006 4:29 am ]
Post subject: 
When I had the drum sanders I still did most of my gross thinning with the Safe-T planer or hand plane, the drum sanders are actually finishing sanders, and are not really meant to hog off a lot of wood. Just to put an even finish on it.

Hesh, I just noticed your new signature, luckily my mahogany stash is the whole Atlantic Ocean away from you so you'll need very long arms!

Colin
Author:  Colby Horton [ Fri Jul 14, 2006 7:26 am ]
Post subject: 
Yes, I also love the wagner drill press planer. It is the only thing I have used for all of my guitars until now. However, on some hardwoods it will leave some seriously bad marks that can be murder to remove by hand. It works great with tops, and softer hardwoods like mahogany and maple. But, I have used it on cocobolo back & sides and ebony fingerboards and bridges and it does not work well with these. It leaves a really rough surface that almost can't be removed with a scraper. I used to use a portable belt sander to cleanup but I hate using those on guitar woods.
Author:  Michael McBroom [ Fri Jul 14, 2006 7:44 am ]
Post subject: 
I fell into a sweet deal on a used Performax 16-32 a couple years ago. Cost me less than a new 10-20, and the deal included outrigger tables and a box of belts. If I wouldn't have found such a deal on the 16-32, I probably would have tried building my own, because I didn't know how well a 10-20 works using the two-pass method. Glad to read it works well.

True, sanding belts can be pricey, but there are alternatives. You can cut your own, which a lot of folks do, saving a substantial chunk of change. You can also clean up the gummed up ones by submersing them in turpentine or mineral spirits and letting them soak. I was told that the latter tip is in the Delta manual. It works great, too. I've been able to recycle fouled belts that way, getting more life out of them.

I have recently begun joining top and back sets before thicknessing them at all. This makes it easier to eliminate the slight irregularities that may occur during the glue-up process without having to worry about getting the set too thin.

As soon as the saw marks are gone from both sides of a top set, I chose which side will be the show side, and don't sand down that side anymore. I've learned the hard way that often slight flaws in an otherwise clean set of spruce especially can begin to show, oftening becoming more evident as thicknessing progresses.

For the back set, I've chosen the show side before joining, and I stop sanding it down as soon as the saw marks are gone to reduce the possibilities of the bookmatch drifting away, which can happen if the set isn't perfectly quartersawn.

Best,

Michael
Author:  vandenboom [ Fri Jul 14, 2006 10:35 am ]
Post subject: 
Thanks Phil
mmmm....never occurred to me, but that makes sense. Yet those who can drum sand the whole width in a single pass have not observed any problems as a result of this.
So it would seem that if you take it easy and don't bite off too much in a pass, that it will probably work fine in both situations (i.e. one pass or two).
Thanks. vandenboom38912.8398611111
Author:  vandenboom [ Fri Jul 14, 2006 10:40 am ]
Post subject: 
Thanks Serge - yes I had already done a bit of searching on this topic, and came across your design and a few others. I am leaning towards making my own at this stage - it does not seem too difficult or expensive and should not take more than 1-2 days. So thanks for your encouragement on this approach.
Author:  vandenboom [ Fri Jul 14, 2006 10:58 am ]
Post subject: 
Thanks Robbie. I certainly did not intend using the drum sander at the 5mm stage for the reasons you gave.
I have a Safe-T-Planer and it has worked well for me on a number of things. However, the 2 limitations I have in using it are
(i) throat size on my drill press is only 6", though it would clearly be cheaper to exchange my drill press for something with 8.5"+ throat, than to buy an off the shelf drum sander.
(ii) it has not worked well on some hardwoods. (Someone else referred to this difficulty on this post.) I used it to plane down some Tasmanian Blackwood sides and it took out some chunks. But I must admit, I don't think I get the blades as sharp as they ought to be, so that could be the issue here. I also find that if I am trying to take off just a whisker, that it tends to scour across the surface and sometimes even jam. Perhaps this is due to my drill press being a bit sloppy, or alternatively, perhaps a whisker would be better removed by scraping.

If I could make the Safe-T-Planer really work for me in conjunction with some sanding/scraping, I would be happy to use it and forget about the drum sander.
Author:  vandenboom [ Fri Jul 14, 2006 11:03 am ]
Post subject: 
Thanks Colin - yes this was my intended approach. I have a Safe-T-Planer, but my drill press only has a 6" throat. So one of my questions was - how much do you plane off before joining the two halves. Other replies have indicated that 3.5mm is about the limit.

What is your experience with the Safe-T-Planer on hardwoods? How thin would you go with the Safe-T-Planer before drum sanding for top, back and sides?
Author:  Dave-SKG [ Fri Jul 14, 2006 11:00 pm ]
Post subject: 
or you can just buy my Delta 18-36 it's in great shape, just needs a new pulley (for the up and down table motion)and some cleaning. It has NOT seen more than 20 guitars worth of use since I bought it 3 years ago( I had surgery and didn't build for about a year)I will sell it for $400 you pay shipping or pick it up.


Didn't notice you were located in Australia...oh well...never mind... Dave-SKG38913.3344560185
Author:  old man [ Sat Jul 15, 2006 2:41 pm ]
Post subject: 
I'm using my home made sander too. It is 20" wide (sanding surface). It works great!!!   I've done all the thicknessing for three dreds and haven't had to change the paper yet. Of course, I'm doing cherry which isn't oily, so I haven't had to clear a single clog. I do make many passes, but it really works well. I have 100 grit velcro backed paper on it, made in Canada, I think.   Also, the dust collection with just a shop vac works very well with it.






Ron

Author:  Serge Poirier [ Sat Jul 15, 2006 2:52 pm ]
Post subject: 
Ron, what size motor you have on yours please?
Author:  old man [ Sat Jul 15, 2006 3:35 pm ]
Post subject: 
I can look tomorrow, but I think it is 1 1/2 hp.

Ron
Author:  Serge Poirier [ Sat Jul 15, 2006 7:02 pm ]
Post subject: 
Thanks Ron, mine being 1/2 hp is probably under powered, i'll upgrade when i put my hands on a bigger one!
Page 1 of 1 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/