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Cross-grain sanding: Redwood

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Total Posts: 165
I'm getting ready to start sanding my pretty redwood top, prior to finishing.
It is commonly said that cross-grain sanding on Spruce is a good practice; I'm wondering if Redwood can be treated the same.

Feb 27, 10 | 6:59 am
Ken Cierp

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"It is commonly said that cross-grain sanding on Spruce is a good practice"

It is???

That should say -- cross-grain sanding on Spruce is an acceptable "corrective action" practice if you have created dips in the surface. The dips are caused when the there is excessively soft grain which is unusal. Avoid using paper of less then 150 grit and there will not be problems.

One guy who have NEVER sanded cross grain (since it can cause a real appearance mess under the finish)

Kenneth Michael Guitars est. 1978

Feb 27, 10 | 7:26 am

Total Topics: 34
Total Posts: 165
Ken - I have read about the cross-grain sanding on this Forum, on, and I think in Somogyi's latest books. I may have read those articles out of context and I should re-check them. The process is certainly counter-intuitive.

What you say makes good sense to me. Onward, with the grain!! :-)

Feb 27, 10 | 7:36 am
Ken Cierp

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The problem is that the marks you make going cross grain will be more severe in the softer grain which is in fact the basic issue in the first place. Fortunately, life offers compromise (and modern tools) --- the answer is a dual action, commonly called a random orbit sander -- a good one -- one that operates at very high speed RPM. The fact is these tools do sand "cross- grain" during part of their spin cycle. But the action is so "random" and "so breif" no scratch pattern (that our eyes can detect) is left on the surface.

Certainly just my opinion -- but having constructed and finished and sold, all sorts of wood products, my conclusion is cross grain sanding is not a method I support as a normal processing step for any wood.


Kenneth Michael Guitars est. 1978

Feb 27, 10 | 8:04 am
blues creek guitars Authorized Martin Repair Ctr

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I read about this technique and questioned the validity of it. I tried it and it works very well on spruce. I do not recommend this where you will stain but on a natural finish on spruce it works very well. FRETS.COM 's Frank Ford is a world known luthier and questioned this practice but it does work. It went against my belief but I agree it is a good technique . The top was DEAD flat and under a high Gloss was so pure in its reflective properties. I will do this again for sure.
john hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center

Feb 27, 10 | 10:49 am
Ken Cierp

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Total Posts: 2262
Yep -- here's the article -- 1999

Tried it did not like it, made no sense when I can use a RO sander and get great results -- different strokes for different folks. Some good ideas for simple sanding blocks in the article -- I use a the pink or blue insulating foam and cork covered blocks too.


Kenneth Michael Guitars est. 1978

Feb 27, 10 | 11:50 am
Bill Cory

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Total Posts: 3584
I used cross-grain sanding on red spruce, but not on any softer woods. It provided a smooth top with no ridges, but I erred by skipping a grit or two, or did an incomplete job of sanding in some way, so there were some fine lines that will show forever underneath the perfectly smooth surface.

Live and learn.


Feb 27, 10 | 1:26 pm

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Total Posts: 480
In places where I have to flatten the surface of spruce I do sand across the grain and it works fine for me. As soon it is flat I turn to sanding along the grain. Take care you don't push too hard or you will scoop out the softer parts of the spruce.

Cannot tell you anything about working on redwood though.

But Ken has a point that (cross-sanding with the too coarse sandpaper) you can end up with visable scratches under the finish. But I use 150# paper and definitely have no marks in my tops. But hey, I have no productiondeadline and take my time for it.


Feb 28, 10 | 1:44 am

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Total Posts: 295
I always start my sanding with my RO sander using 150 and then 220 to level. After that I switch back to 150 on a block and sand with the grain. I then wet the wood to raise the grain, dry with a blow drier and then switch to 220 and stay with the grain. I repeat with 320 and 400.

This works well for me.


Feb 28, 10 | 5:48 am
Running Dog

Total Topics: 1
Total Posts: 103
Cross-grain sanding removes material pretty quickly, which is great for some situations. But always finish WITH the grain! Redwood sands quickly anyway; I don't think I've ever sanded cross-grain once it comes out of the drum sander.

Mar 01, 10 | 11:56 am

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