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The purpose of candling a joint is not to get an invisible glue line, it's to get the best joint possible. An invisible glue line is not proof of a perfect glue joint, it just shows that you have an invisible glue line. You may still have a joint that had uneven pressure when clamped, and still get an invisible glue line.


This demonstrates quite precisely my point.

Putting the plates on a window to check the seam is too easy to do to not do it.

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Alain Moisan
Former full time builder of Acoustics, Classicals and Flamencos.
(Now building just for fun!)

I've only joined a half-dozen tops/backs and have always "candled" then against the glass portion of my "screen door", which is at eye level. Unfortunately, my front door is a bit of a walk from where I do my shooting work, so as I fine tune the joint I find I get a bit of exercise walking back and forth between my front door and my work area.

To avoid the walk, on the first 3 I joined I tried holding the plates together at arm's length and holding them up to light, but I encountered two problems. First, I found it VERY difficult to hold the plates together perfectly in alignment while moving my head and/or the plates up and down to inspect the entire length of the joint. I always ended up with a little movement and would end up placing the plates back on a flat surface, pressing them together and starting over.

The second and more important problem I encountered is that when I thought I had a good joint, I would walk to the front door and inspect it against the glass and ALWAYS found gaps I had not seen when holding them up to the light. My conclusion was that the movement I always experienced holding the joint up to the light probably resulted in me trying to correct gaps that weren't really gaps, and as a result creating more real gaps.

Candling against a true flat glass plate where I can press the plates together using light pressure just seams like a no-brainer for someone like me. A light table is appealing since I could situate it close to my work area and avoid the walks. I have no doubt experienced folks can get a good joint with the right technique by holding the plates together with a light source behind them, but I know from experience I can't. So until such time as I can develop that technique, it's the front door for me. IMO it's a small price to pay for the peace of mind that comes from knowing I achieved a very good joint.

That be my $0.02.

Hey everyone -

Today I joined the top. It was lutz from Shane, and a little bit thicker than the bubinga too. Not only did I get a completely dark join line on the light table, but it took all of about 10-15 minutes of messing with it. And yes, without the light table, I probably would have joined them earlier and less perfectly.

If I can figure out room for it, I'll keep using it, but I agree with Charlie. I've got to get it closer to my bench. My legs are sore!

Mike

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Mike Lindstrom

Filippo, I don't care if your plane is turbo charged with polished aluminum wheels on it, I still feel that checking the seam using a light table or a large window is always going to be more reliable than holding the plate at arms length.

Just try and compare, it's easy enough. If your seams are good when checking both at arms lenght and using a window, than keep using your method and sleep tight. What more can I say?

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Alain Moisan
Former full time builder of Acoustics, Classicals and Flamencos.
(Now building just for fun!)

C'mon, you don't NEED a light box to get a perfect joint. That statement is just false.

Whatever...

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Alain Moisan
Former full time builder of Acoustics, Classicals and Flamencos.
(Now building just for fun!)

Of course you don't NEED a light table or window to get a perfect joint, just like you don't NEED a sharpening guide to put a great cutting edge on your chisels and irons. You don't NEED a radius dish to get a tight fit between top and rim. You don't NEED a shooting board to cut a straight, true edge on your plates. You don't NEED a Fox style bender to accurately bend your sides without breaking them.

I saw a glass desk that resembles a small drafting table at Sam's club Sat. for around $70 that would work great as a light table with some lights below it. I guess you all that don't have a light box don't do any tracings for designing your own inlays then or read your Xrays from the Docs.

Couldn't one just go to the junkyard,
get a sliding window,
support both ends,
and stick a light under it,
then stash the slider up against the wall to store?
That's what I'll do,
someday...........
Maybe.

That's just what I'm thinking, Todd. I like the box and it's helping me do a better job, but I don't have the space. I'm going to redo it in a much narrower version.

Mike

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Mike Lindstrom

I typically use a window also, but Todds right IMO. Also you can tell by feeling the resistance of rubbing the plates together along the joint. When things are perfect there's a lot more resistance when sliding the plates along the joint than when they're not so perfect.

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Jim Watts
http://jameswattsguitars.com

What?? No pictures at this thread!?