Sanding Redwood- Cmplex Grain Keeps Raising

[Jon Singh]

Hey All,

Running into a predicament, a friend of mine wanted desk made from redwood planks from the local bigbox with some really nice figured grain. We took it, planed it, and glued up the lumber to form a nice desktop. The issue I'm running into is on the sanding, I literally sand and sand and sand, a few hours later ill come out to the garage and the figured grain itself is raised every so slightly, giving everything that just 'slightly bumpy feel'. This is only where the grain gets intricate, the straight grain stays nice and smooth. I've thought about just going at it with as sharp as possible smoothing plane to see if itl help. It's just odd because it feels smooth, a few hours later its raised again, makes me wonder how dried this lumber really was or if the humidity around my house is just changing that much to have that much of an interaction with the wood. I myself really primarily work with walnut,maple,oak and anything I've ever built with pine is usually garage type stuff so i just haven't paid attention this closely to these types of materials when trying to get more in-house furniture quality.

Just wanted to get some thoughts from you folks with more experience with me.

Jon

[Zac wingert]

I think what is happening is the sanding is taking away more material given the difference in hardness between the early wood and late wood. You could hand plane or even finish straight of a machine planer and then lightly sand between coats.

I think that’s just a side effect of working with big box quality material. You are not going to get fine furniture results with it. But realistically, if you just finish straight off the planer or just finish with the uneven material after sanding, it’ll all be ok. Just not fine furniture level, which is ok. If you want perfection you can’t use that kind of material. Those trees were plantation grown and very rapidly. Which is ok. We don’t want the old growth forest sawn down to death. Just my thoughts

[Jim Matthews]

Try using a Sandvik carbide scraper instead of sandpaper. There will be a more favorable direction, with the grain.

With "reluctant" wood species a washcoat of thinned Shellac may hold things down as a sanding sealer.

[roger wiegand]

A plane or scraper may work better, the wash coat of shellac will probably help. Are you using a powered sander? If so, does it have a flexible pad on it, like velcro? If so, you may improve your results by fixing a piece of sandpaper to rigid flat surface, like a flat board, and sanding by hand. I'd dampen the surface and then let it dry to raise the grain, then sand gently with the board-mounted paper to knock down only the high spots.

[Bill Dufour]

No location listed. so how is you humidity?
How dry is the wood? HD here has most redwood soaking wet. You can feel the dampness if you pick up a piece.
Bil lD

[Bill Yacey]

A plane or scraper may work better, the wash coat of shellac will probably help. Are you using a powered sander? If so, does it have a flexible pad on it, like velcro? If so, you may improve your results by fixing a piece of sandpaper to rigid flat surface, like a flat board, and sanding by hand. I'd dampen the surface and then let it dry to raise the grain, then sand gently with the board-mounted paper to knock down only the high spots.


Similar to what I would suggest- raising the grain with water and then following up with a scraper plane, repeat as necessary. At some point the wild grain will equalise in expansion with the surrounding straight grain.

[glenn bradley]

I literally sand and sand and sand, a few hours later ill come out to the garage and the figured grain itself is raised every so slightly, giving everything that just 'slightly bumpy feel'

Softer woods, especially those with soft and hard combination figure like redwood don't sand like woods of a more consistent texture. In something like QSWO the material can support the sanding pad and gives a pretty consistent surface. The redwood (or pine or hemlock or cedar or whatever) has very soft areas between not-so-soft areas. A larger, harder, sanding block is a good solution. One needs to sand the harder material down to be even with the softer material without the pad dipping down into the more easily sanded parts of the wood. Try sticking a strip from a sheet of abrasive to a long (10" or more) shop made block on a test piece to see the difference.

[Stephen Rosenthal]

Like Bill I’m in NoCal and stopped buying Big Box lumber for anything but general construction projects - way too wet. You can try Roger’s suggestion of dampening the surface, but I’ll bet your redwood has a high moisture content that is raising the grain and will compound your problems as the piece ages. I always check each board with my moisture meter, which is a good general practice regardless of the wood or where you buy it. When I do use redwood for furniture I pay upwards of $8.00/bd. ft. For that I can get an 8 foot length of 2x8 at HD or Lowe’s.

[Jon Singh]

Thanks alot everyone, im gonna give it a go with a scraper plane and then a really light sanding after with a hard pad on the sander to just finish it up. Pretty interesting running into this, definitely learned something new here.

[John Lanciani]

If you don’t know the moisture content of the wood you’re working with you are just wasting your time. You’re just chasing your tail right this minute.

[Bill Dufour]

I would leave the wood outside, in a shady place, for a month until you know it is dry. Or put it in the rafters for that time right now. Longer in winter. That is what I try to do with fence lumber. I buy extra and return the badly twisted stuff for a refund after it dries. Direct sun when it is over 100 will dry it too fast and cause even more bending and twisting.
Bill D

[Mike Henderson]

I did some work recently with big box figured redwood. I put it in the sun to dry it further. When I used it, I wet the surface after sanding and then put it out in the sun again to dry. A final sanding with high grit sandpaper (I think it was 400) smoothed it out nicely and it didn't get fuzzy later.

Mike

[Richard Coers]

I know this may not be a popular idea in the power tools section, but how about a wood sanding block and hand sanding. Get some garnet sandpaper if you really want to go old school.

[Jon Singh]

Thanks all, I think i'll let it sit outside a while, it's true I dont know the moisture content at all of the wood, we do live in a very hot and dry desert climate out in this area of SoCal but I have no clue how long the wood has sat there, could be really old but could have been fresh shipped from god knows where. Looks like moisture meter is now on my short list...

[Mel Fulks]

Take a look at the other side. Maybe you have the wrong side up. If the wood is flat-sawn ,the "bark side" must be up.

[John Lanciani]

Take a look at the other side. Maybe you have the wrong side up. If the wood is flat-sawn ,the "bark side" must be up.

Why? Every table I've ever built has the boards heart side up and I've never had any issues related to which side is up.