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Posted

Gentlemen,I bought some construction grade spruce the other day and intend to use it for a top in an archtop project I just started,inspired by the Benedetto Pine guitar ,anyways ,I also read that moisture content should be low to avoid warping or shrinking ,i dont know,thing is I dont know how to measure the moisture, i would like some advice on that,also would it be too bad really using this piece? what could be the worse?.

Posted

Gentlemen,I bought some construction grade spruce the other day and intend to use it for a top in an archtop project I just started,inspired by the Benedetto Pine guitar ,anyways ,I also read that moisture content should be low to avoid warping or shrinking ,i dont know,thing is I dont know how to measure the moisture, i would like some advice on that,also would it be too bad really using this piece? what could be the worse?.

Moisture content and shrinkage/warpage becomes much more critical when you work with thin wood. You can buy a moisture meter to test for moisture(most woodworking stores carry these). Even after testing and finding the wood to have a low moisture content you need to allow the wood to aclimate to your work space(give it a few months minimum). During the time it is getting used to your shop you can monitor it for movement/shrinkage.

The extream example(worst case) of how critical this is- Lets say your instrument is left in a hot environment(direct sunlight very hot day, or maybe your car on a hot day). This can dry thin wood to basically 0 moisture and force any final shrinkage and warpage. This would be extream, but believe it or not some people bake the last of the moisture out of the wood to force the wood to final shrinkage. As soon as it is put to 0 moisture it will draw moisture back in(based on humidity), but in theory it will not become as damaged under a future heating event.(this kind of drying would be insane on wood thicker than maybe 3/16", and shouldn't be attempted unless the wood is extreamly dry to begin with).

Peace,Rich

Posted

What Rich Said.

I don't have a moisture meter, but I do have enough time to leave stuff lying around for months and months and months before building with it, so that helps. Honestly, if the wood's dry, you store it stickered and weighted (good practice for pre-sized pieces), it should acclimate within 3-4 weeks. For an acoustic guitar top, 4 weeks should get it from wet to pretty much dry, because it's v.v. thin.

A 'cheap' tip, if you don't have a moisture meter: get an accurate scale, weigh the wood (the smaller the minimum measurement increment, the better). Weight it again after a week. Weight change? It's losing moisture. Repeat until weight remains unchanged.

Posted

Rich, could you elaborate on the baking method you mentioned. Temperatures, times, that sort of thing would be helpfull - as well as whether or not the wood should be weighted while in the oven. Thank you.

Nate Robinson :D

Posted

Rich, could you elaborate on the baking method you mentioned. Temperatures, times, that sort of thing would be helpfull - as well as whether or not the wood should be weighted while in the oven. Thank you.

Nate Robinson :D

Nate,

Take this for what it is worth. I have only done this once, and although it worked well there may very well be a better way to do this(let me do this a few more times and I will feel better about my method).

Temp=200 deg.

Time=1 hour

The method I used went like this. I pre-heated the oven using a thermometer to confirm the temp was 200. I placed the top flat with no metal to wood contact(no added weight). I found I really did not need to keep the oven on because the temp. stayed plenty warm(I tried to avoid letting the elements produce extra direct heat, some form of sheild between the wood and element would be good insurance?.). When I removed the wood from the oven I did weight and sticker the pieces lightly. Now just to be clear the wood I used was extreamly well dried to begin with and was at .140" thick. The more I thought about the heat and how it compairs to the temp used during bending(300deg-ish) the less fear I had of damage.

Hope that helps. Maybe Mattia could add some input. I think he was going to give this a shot.

Peace,Rich

Peace,Rich

Posted

I am getting me a moisture reader, tomorrow!! about the oven you guys are talking ,I presume is a special one, or just my kitchen oven would work? sorry for my ignorance.

Posted

I just baked my first top on Sunday, as it happens. Used my regular houshold oven (which is a bit small, so I had to leave the door propped open and some foil on it to prevent heat escaping). Pre-heated until it hit 100 degrees centigrade (113 farenheit or so), put the wood in there stickered (few scrap bits of pine between the halves, scrap of MDF on top because I'm paranoid; I don't think it was necessary), left it in there with the oven on as low as it would go, especially because the door was slightly ajar, and kept an eye on the temp.

Initial non-measured impressions (don't have stuff set up for measurements) are that it's slightly stiffer, but not hugely different, tonally.

Posted

I just baked my first top on Sunday, as it happens. Used my regular houshold oven (which is a bit small, so I had to leave the door propped open and some foil on it to prevent heat escaping). Pre-heated until it hit 100 degrees centigrade (113 farenheit or so), put the wood in there stickered (few scrap bits of pine between the halves, scrap of MDF on top because I'm paranoid; I don't think it was necessary), left it in there with the oven on as low as it would go, especially because the door was slightly ajar, and kept an eye on the temp.

Initial non-measured impressions (don't have stuff set up for measurements) are that it's slightly stiffer, but not hugely different, tonally.

Mattia,

Did you keep the temp that low through the process? How long did you keep it in the oven? I was at 200 for an hour. Do you think lower temp for a longer period would be safer? Did you notice any changes in the wood as far as shrinkage or warpage? What species? Boy am I full of questions or what.

Peace, Rich

Posted

Rich, 100 degrees C, which is 213 Farenheit, sorry about the typo! Not low ;-)

And yes, kept it constant for the entire hour, checking every few minutes to make sure it stayed put. Top was WRC, and I didn't measure any significant shrinkage using my bog-standard ruler (my own stupid fault for not marking the exact place I measure pre-bake; next time better!). As said, it felt a bit stiffer, other than that...

Posted

Rich, 100 degrees C, which is 213 Farenheit, sorry about the typo! Not low ;-)

And yes, kept it constant for the entire hour, checking every few minutes to make sure it stayed put. Top was WRC, and I didn't measure any significant shrinkage using my bog-standard ruler (my own stupid fault for not marking the exact place I measure pre-bake; next time better!). As said, it felt a bit stiffer, other than that...

Cool, sounds like you actually ran just a tiny bit hotter than me. Mine was WRC also. I didn't notice any significant shrinkage. As a matter of fact I found it to be just slightly stiffer when it was finished. The difference became more appearant when I braced it and compaired it to the top I had just finished. It was just a small change, but was enough to allow for modified bracing(slightly thinner) and slight thickness decrease. I am going to try out a Sitka top next and see how it compairs.

Peace,Rich

Posted

How thin are you taking that top? Be careful with those knots. The wood is rift sawn with a good portion really flat sawn. Hopefully that runout does not seperate with wood that thin and carved. I sure hope for the best. Your work is looking pretty nice. In the future you might want to look for quartersawn wood that is free of knots. It will be a much better platform for your hard work. It would be cool to see more pics as you make progress.

P.S. Don't even worry about baking the top. It is just a quirky little option, and by no means a requirement. I would never subject a glue joint to that anyway.

Peace,Rich

Posted

I carved it to 1/4 inch,and still struglin with the inside,but I see it also as a practice for when I get a better top.

Posted

Olyen:

I'm feeling that alot myself. I look at the beautiful - if not superb - instruments that seem to be childs play for other members, and think, " I can approach that". But at the end of the day I always go cheap first. In my experience the cost of a guitar isn't in the wood, but in the hardware. Obviously I haven't purchased first rate wood yet, but then my skills don't necesitate that yet. My big problem is self control. I see all these wonderful instruments being made and want to jump right to that level - after all it doesn't look that hard! But without the proper knowledge, the best tools in the world aren't going to get me any closer to that kind of craftsmanship. That's where members such as fryovanni and mattia make such an impact on me. They show that they have the ability to push my work so far into the mud it makes me fart dust balls, and at the same time encourage and propel me to ask "stupid" questions. So - first rate wood - who cares? Do what you can with what you have and keep the learning curve steep.

Good Luck

Nate Robinson :D

Posted

I agree 100% with you on that. What can I say,a luthier wanna be, thats me. I am still working on smothing the inside of the top and later another nighmare,the bracing, i ll post pics of that too.

Posted

Push what in where? Thats kinda silly to say since we are all in the same boat(just doing what we can to get better). As far as using high grade woods. Well it can get kinda crazy expensive for some pieces. I would say though there are some attributes that make wood easyier to work with and will be structurally suitable for your hard work. You don't need 25+ growth rings per inch, colorless, flawless grain with 0 compression- errr... and Bearclaw figure throughout. You could pay $700 for a piece like that. A "fair" piece(totally suited for an instrument) with minimal runout 10-15 growth rings per inch, no knots, but maybe a little color and slight compression will run about 5-6% what the "high end" material costs. The material will carve better(smoother) and you won't have to worry about the wood defects being structurally unstable.

So maybe more on point here. You mentioned you are having a time with the carving. What method are you using- tools and such. Maybe there is some tricks we could pass on to help your process.

Rob,

But, for a real guitar you want real quartersawn wood. Knots or not (sorry). That's the most important thing however dry it is.
. I would take dry flat over wet quarter, but knot moist flat over damp rift just about anyday---- but knot today. Of course that really depends on how nice the figure is. :D

Peace,Rich

BTW: Nate: I just finished binding my latest acoustic. I used probably the most expensive wood I have ever used on this one(Snakewood and Quilted Sapele), and it scared the cr..p out of me each and every step of the way(mainly because I would be hard pressed to replace it if I screwed up, and the type of wood does not hide mistakes well at all). I much prefer not to have that pressure(my next one is going to be made of more common woods).

Posted

well,I made the jig with the pin aligned to the drill bit in the Drill press with a stop in 1/4 inch, the i used an old chisel that i got i dont know were with a plastic hammer to get rid of the chunks,it worked pretty good,then became tricky cause i dont wanna thin the platetoo much,I was using my orbital sander but took too long ,so i went and chiseled again,problem is I got some chips that left little holes,anyways after that i sanded and it seems to be oK, i only hope that I dont cry when i have to cothe same in the maple back,i arved maple before but always just the top and used even a grinder with the sanding device,didnt have to follow any pattern or thickness ,this is very different, by the way, i already ordered some spruce from someone on ebay ,I know it will be better tonewood and hopefully i ll heve a better idea of what to do by then.

  • 2 weeks later...
Posted

well,I made the jig with the pin aligned to the drill bit in the Drill press with a stop in 1/4 inch, the i used an old chisel that i got i dont know were with a plastic hammer to get rid of the chunks,it worked pretty good,then became tricky cause i dont wanna thin the platetoo much,I was using my orbital sander but took too long ,so i went and chiseled again,problem is I got some chips that left little holes,anyways after that i sanded and it seems to be oK, i only hope that I dont cry when i have to cothe same in the maple back,i arved maple before but always just the top and used even a grinder with the sanding device,didnt have to follow any pattern or thickness ,this is very different, by the way, i already ordered some spruce from someone on ebay ,I know it will be better tonewood and hopefully i ll heve a better idea of what to do by then.

Removing the bulk of the material by drilling it out in a stepped pattern is not a bad way to go. As you get used to using a chisel and keeping it sharp. That part will go better also. After ruff shaping with a chisel a scrape is a nice way to bring it to smooth, and then finish with a bit of sanding. Another option would be to use a router to your pattern, and then light chisel and scrapers. These are the two methods I would use. I know some guys use grinding methods, but I am not sure how they keep it accurate. You may want to look into quality chisels. With the right technique they really make short work of removing material, and can be really accurate. BTW; You should need little more than hand pressure to use a good sharp chisel. If you are having to beat on it try giving it a good sharp edge(some harder woods do require a bit of tapping, but the cut should still go without heavy force required). Spruce will carve like butter compaired to Harder Maples.

Peace,Rich

  • 4 weeks later...
Posted

Olyen:

I'm feeling that alot myself. I look at the beautiful - if not superb - instruments that seem to be childs play for other members, and think, " I can approach that". But at the end of the day I always go cheap first. In my experience the cost of a guitar isn't in the wood, but in the hardware. Obviously I haven't purchased first rate wood yet, but then my skills don't necesitate that yet. My big problem is self control. I see all these wonderful instruments being made and want to jump right to that level - after all it doesn't look that hard! But without the proper knowledge, the best tools in the world aren't going to get me any closer to that kind of craftsmanship. That's where members such as fryovanni and mattia make such an impact on me. They show that they have the ability to push my work so far into the mud it makes me fart dust balls, and at the same time encourage and propel me to ask "stupid" questions. So - first rate wood - who cares? Do what you can with what you have and keep the learning curve steep.

Good Luck

Nate Robinson :D

Nate,

A few comments:

1. I wouldnt use highest grade wood for your first instruments but at the same time dont use a grade of wood that is going to be hard to work and will give poor results. When I started off I used mainly "AA" grade tops. I think I wrote off two Sitka tops in the early days but written off tops will always get used for patching and making grafts for other tops. They can also get hung on your workshop wall to remind you not to make the same mistake again!!!!

2. Tools..get the best you can afford. Working an "AA" top with a chisel that wont hold an edge or a plane that chatters is going to get you very p***d off and quickly dull any enthusiasm for buiding guitars. If youre on a limited budget aim for a basic set of good tools than a workshop full of poor quality ones. A decent smoothing plane might require a high intial outlay but the thing is going to last you all your life.

3. If and when you can afford it...buy yourself a router. Its the most versatile and useful tool you can have in a luthiers workshop.

Cheers Martin

here s some pics of the actual piece,I guess it s late to bakeit now.

How thin are you taking that top? Be careful with those knots. The wood is rift sawn with a good portion really flat sawn. Hopefully that runout does not seperate with wood that thin and carved. I sure hope for the best. Your work is looking pretty nice. In the future you might want to look for quartersawn wood that is free of knots. It will be a much better platform for your hard work. It would be cool to see more pics as you make progress.

P.S. Don't even worry about baking the top. It is just a quirky little option, and by no means a requirement. I would never subject a glue joint to that anyway.

Peace,Rich

I agree with Rich, those knots are going to cause you grief. You've gone to alot of effort and it looks good but you'll get alot more pleasure out of a piece of quarter sawn spruce. If you have a hard on for using ply then Id go for top quality marine ply....alot more stable and less knotty than construction grade.

Cheers

Olven,

Is that piece of spruce solid or is it ply? I was assuming it was ply in my last post.

Cheers Martin

Posted

Olven,

Is that piece of spruce solid or is it ply? I was assuming it was ply in my last post.

Cheers Martin

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