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Cutting Soundports-- How do you do it?
http://w-ww.luthiersforum.com/forum/viewtopic.php?f=10102&t=11399		 Page 1 of 2
Author:  GregG [ Tue Mar 27, 2007 6:54 am ]
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I'll be cutting out soundports in two new guitars this week and was just wondering what you guys use, or have found is the cleanest way to do this operation.

Thanks,
Greg
Author:  j.Brown [ Tue Mar 27, 2007 7:15 am ]
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All mine have been freehand with a dremel and a downcut router bit, then cleaned up with files and sandpaper, but this method is not for the faint of heart.
Dont' forget to laminate some sort of backing on the inside to help with chipout and strengthen the area with the hole in the side of the guitar.
-j.
Author:  Andy Zimmerman [ Tue Mar 27, 2007 7:31 am ]
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For my dog print soundport I have a paper copy of the design that I stick to
the side with spray adhesive. I then drill a hole in the center of each piece
and use files and rasps to extend the hole to the edge of the design. I finish
up by sanding and rounding over the edge.

Since my sides are like Ervins, they are nice and stiff and can handle the
drilling and filing
Author:  Steve Saville [ Tue Mar 27, 2007 7:32 am ]
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After I draw the round shape in pencil, I drill several holes just shy of the line. (I make the hole about 1".)Using a fine tooth jig saw blade, I cut between the holes. Then I take a 1/2" to 3/4" sanding drum and enlarge the hole to the drawn circle.
Author:  Terry Stowell [ Tue Mar 27, 2007 9:29 am ]
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I think there's more questions to be answered. For example, do you cut out before bending? If so, do you laminate before bending? If so, how do you compensate for the bulk underneath? On and on.

Can someone step up with a GOOD pictorial?
Author:  Pwoolson [ Tue Mar 27, 2007 10:03 am ]
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Here's my method:
First, I glue on a cross grained patch of spruce. You can use anything but I like the interiors of my guitars to be light in color so all of my braces and linings are light.

From that point I cut the hole. I just use a simple template with a pattern bit (spiral to prevent chipout)

Now these next steps are not necessary but it's something I do. At this point I bind the soundhole. I wish it was half as easy as it looks. It's very tricky to get the ends to work out the way they should.

And the bound soundhole:

From this point I go to the bender. I have a little plug that goes into the soundhole to help prevent the binding from pulling away during the bend. Other than that, it's a traditional bend.
Hope that helps.
Author:  Andy Zimmerman [ Tue Mar 27, 2007 10:05 am ]
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I actually do all of it after bending, after lamination etc.
It can certainly be done either way. Paul method looks very nice
Author:  Pwoolson [ Tue Mar 27, 2007 10:08 am ]
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Yes, Andy is correct on all accounts for an unbound hole.But it's next to impossible to bind the hole after the side is bent. (Ask me how I know this). So if you aren't binding, do it either way, if you are, please take my advice and do so before bending. You'll save yourself a lot of frustration.
Author:  JohnAbercrombie [ Tue Mar 27, 2007 10:10 am ]
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Paul-
Do you feather the ends of the spruce patch before bending?

If not, how do you deal with the linings where they meet the patch?

Thanks
John
Author:  Pwoolson [ Tue Mar 27, 2007 10:14 am ]
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John, I cut the patch "up" from the edge the height of the linings. So the lining will not be interupted and the patch will just but up to it. I do this after bending and right at the point of lining installation.
Author:  JohnAbercrombie [ Tue Mar 27, 2007 10:25 am ]
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Thanks for the lining info, Paul.
Binding the hole is a nice touch- as you say, pretty tough to do after bending.
This is all in the future for me, though with laminated sides an 'afterthought' soundport is a possibility, I guess.
Cheers
John
Author:  Terry Stowell [ Tue Mar 27, 2007 10:50 am ]
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roughly, how thick is your patch Paul? I assume bending doesn't produce and bumps at the ends of the patch?
Author:  Pwoolson [ Tue Mar 27, 2007 10:56 am ]
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Terry, it's usually about .040". Since it is cross grained it yields very easily to the bend and doesn't produce any facets. I was a bit concerned that the upper bout bend would be off but I haven't noticed a bit of problem with it sitting in the mold just right.
Author:  Terry Stowell [ Tue Mar 27, 2007 11:23 am ]
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Thanks Paul. You've contributed to helping others to proceed with confidence. I appreciate you taking the time posting the pictures.
Author:  Anthony Z [ Tue Mar 27, 2007 11:32 am ]
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Paul I second the thanks for the pictures and explanation.

When you bind the soundport do you do it veneer layer by layer or with a laminated sandwich?

Which ever way you do it -- there must be a lot of fit, cut, fit, cut till you get it just perfect as it must be tough to dry fit as you go.

Thanks again.
Author:  Pwoolson [ Tue Mar 27, 2007 12:21 pm ]
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Anthony, I've tried it both ways. What I find to be most successful, though most time consuming, it to bind each layer seperately. Fit the maple, glue it in, fit the black, glue it in, fit the koa, glue it in.
Yes, lots and lots of fit, cut, fit, cut, cuss, throw it across the shop, fit a new piece, etc.
Author:  Anthony Z [ Tue Mar 27, 2007 1:05 pm ]
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[QUOTE=Pwoolson] Yes, lots and lots of fit, cut, fit, cut, cuss, throw it across the shop, fit a new piece, etc.[/QUOTE]

Thanks Paul. In hindsight it was a dumb question as I've bound a few f holes on archtops. When doing it with veneers I've found doing it layer by layer works best as well.

Referring the quote above -- I think I understand.
Author:  Terry Stowell [ Tue Mar 27, 2007 11:40 pm ]
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Any other picture/technique posters? It's be nice to seee a pretty thorough treatise on the subject in one thread.

Pix, pix pix please
Author:  Dave Stewart [ Wed Mar 28, 2007 3:18 am ]
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Paul, have you (or anyone) ever done a soundport in an archtop? To my thinking, this might be very effective for the player, since an archtop tends to be a more "projecting" type of instrument.
Author:  Pwoolson [ Wed Mar 28, 2007 3:24 am ]
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Dave, I haven't but I think it's a good idea. Mine are designed to be played pretty much exclusively plugged in so I'm not sure I would gain much from having one. Though I might try it someday just for kicks.
Author:  Howard Klepper [ Wed Mar 28, 2007 3:44 am ]
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If you glue a patch with an edge butted to the liners, or not butted, but running parallel to the grain of the sides, then you should feather the edge to avoid a stress riser and potential for originating a crack.

I use a Forstner or sawtooth bit to bore a round port after bending and laminating (or laminating a patch if it's a single side). Bore from the inside out to minimize chipout. Then I turn a binding ring on the lathe.
Author:  Steve Saville [ Wed Mar 28, 2007 3:57 am ]
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[QUOTE=Howard Klepper] Then I turn a binding ring on the lathe.[/QUOTE]
Dang, that's cool and makes a lot of sense.
No joint line, make it tall and sand to profile.....

If I just knew how to use my lathe better.
Author:  Anthony Z [ Wed Mar 28, 2007 5:29 am ]
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Dave my next archtop I start from scratch will definitely have a soundport as I build mine to be played acoustically or plugged in. I think an archtop would really benefit from having one as the sound develops so far from the player. I don't know if you have looked at any of Linda Manzer or Douglas Harrison (another fine Toronto luthier). Both offer soundports as an option on their archtops. Both will do them louvers.

A recent Guitarmaker had a really art deco'ish archtop on the cover. It had a soundport where the liner was made from a b/w/b veneer sandwich. The edge of the soundport looked like it was cut at about a 45 degree angle which looked really cool. It gives the soundport a bound look without the frustration Paul alluded to above.

Author:  Dave Stewart [ Wed Mar 28, 2007 6:14 am ]
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Thanks Paul


Anthony, good approach to the binding issue. (I tried to find an image online but couldn't). Both Linda and Doug Harrison do fabulous work (although the louvers scare me). The soundport definitly intrigues me, especially after Grit Laskins demonstration of the huge difference in makes. I'll be very interested in how yours turns out.


Cheers


 
Author:  Pwoolson [ Wed Mar 28, 2007 7:08 am ]
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Speaking of louvers, has anyone talked to the folks that put them in to know why they do so? I can't imagine a situation where you wouldn't want the port. I know there are several builders that have dabbled in sliding doors of leather and plastic and the like. I just don't understand that thought process.
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