Candling A Top

[Lucky]

Hi,

I've been struggling with candling my top to perfection. I've tried planing it with a #7 jointer plane, 1200 and 2000 grit sandpaper. I've tried for several hours at a time in four separate occasions and it still isn't perfect with zero light at any point.

How perfect am I shooting for?

Methods to actually achieving perfection?

-Lucky

[tippie53]

I take it your taking about your joint?
If your plane is set up well and I am talking taking a micro scoping cut . Try that. If you are sanding how are you doing this ?
Can you post some pics of your process ? That may help. I use tape and check the joint , if it is closed glue it. Candeling a joint is at best a guess. If you are not holding it perfect you can allow light in.

[Lucky]

Yes, my plane is well set up and cutting shavings so thin they're transparent. I've jointed lots of boards so this isn't uncharted territory. The wood seems to crumble in places. After I got frustrated with the plane I flipped it over and clamped it in a vise and took the wood to the tool, still no luck. Then I laid sandpaper on the upturned plane for a perfectly flat surface and used sandpaper. Each stroke I would hold the boards up to the sky and find the high spot. I did this for several hours. Most of the surfaces are mirror bright but there's still some crumbly. Note: this is torrified red spruce, I don't know if that makes any difference?

I'm thinking what I've got is as good as it's gonna get. It may just be, like you mentioned, I just can't hold the boards steady enough. Perhaps I'm aiming too high and expecting absolute perfection?

[tippie53]

The glue will fill a few thousandth. I think you are most likely over thinking it. Try taping the joint and look at it on a flat surface. Bet it will look a lot better.

[Lucky]

Okay, just by checking the joint on the bench it fits together very well. I think candling against the sun and wobbling around is what was causing me so much heartache. I got it together and she's glued and wrapped up tight. It's nice and dry today so gluing should go well.

I'm going to try jointing the back now, glue up and if I can squeeze it in I'll glue up my scarf and heelblock. The weather is so perfect today.

Thanks

[tippie53]

your not the first one to do this. Congrats and have fun.

[Lucky]

I took a look at the glued joint after it had been clamped for a few hours. It looks fantastic for about 97 percent of the way and then there's a sliver of light. So I took a tiny paintbrush and jammed a tad of glue in the joint. Here's to hoping it works.

This is my first guitar so I'm realizing that every bit is not going to be perfect and I should just get on with it. I've been suffering with paralysis by analysis.

[ruby@magpage.com]

Remember that part of it will be cut out for a soundhole, and part of it will be below the fretboard extension with perhaps a transverse brace and a popsicle brace to hold it together

Ed

[sylvan]

When you plane or sand the edge to get a good joint, don't forget to do them together (side by side) so that when you are done you lay them out in the book match any variation in one is cancelled out by the other.

[Lucky]

I did them "bookmatched" but I really don't think it turned out good enough. In both the top and the back I can see a tiny bit of light in the lower bout. I feel like my efforts of sanding, checking, sanding, and so on aren't really working. It seems like I'm doing it for hours and nothing is really changing. I see the high spot and specifically work on it and nothing really changes. I'm not sure what I'm doing wrong?