Fretboard question

[watergunn]

Another newbie question regarding the fretboard.

Last week I taped the fretboard to the neck and did the final shaping and sanding. The fretboard was perfectly even with the neck edges. Today I was going to glue the fretboard to the neck and in dry fitting I noticed that the fretboard did not meet perfectly with the edges of the neck.

The neck is a hair wider than the fretboard on each side. It is a slight difference but I can feel it. I know that I will need to sand again to get the edges to mate correctly.

Is this normal due to the frets pushing on the ends of the fretboard over the last few days?

I did the frets themselves probably two weeks ago or so.

[tippie53]

don't final size until you glue them together. RH changes will often do this. Neck woods and fretboards often react differently to RH

[watergunn]

It has been raining off and on for a week here. The RH in my basement has only changed 10-15 percent though. It stays right around 35-40 percent.

Should I wait until the weather clears before gluing?

[B. Howard]

A 10 or 15% change in RH is big, bordering on huge. Here is a link to an EMC chart.
http://www.csgnetwork.com/emctablecalc.html
You can see how much the moisture content will change due to temp and RH. Temp has little effect, RH has a big effect. Personally I think anything below 40% shop RH is too low for guitar making, The wood will swell too much when the guitar leaves the shop and enters the real world causing set-up issues, unnecessary stress on joints, etc. Martin keeps their environment at 45-55% RH, I target mine a bit tighter at 45-50%, A lot of custom builders will go for 4o-45%, but few can offer a good reason for this as it applies to lutherie, those are good numbers for a cabinet shop, but not necessarily guitars.

[watergunn]

Ouch!!!

Thanks for the link.

[watergunn]

The rh in the basement has been between 30 and 40. It spiked to around 50 aftr several days of rain. Once the weather passes is back at around 43.

[Tom West]

I concur with Rick on this one, for me 35%RH is what I like to see when gluing bracing for tops and backs. Gluing a bit too dry is a quantum leap better then gluing a bit too wet.
Tom

[tippie53]

I like that 35 to 40 range . I turn my dehumidifiers on full. I like lower RH on brace glue ups.