Sanding Proofgrade

So, I have a number of stains I’d like the proofgrade to absorb, but I’m getting terrible results with how I’m sanding it.

Has anyone else had luck sanding off the finish off a whole board? What grit? How long did it take you? Did you use plywood or hardwood? Were you happy with the results?

I have a stain (Unicorn Spit) that is something in between a stain and a paint. I’ve sanded off the finish (to the point I can’t see any shiny on the board). Stained, sealed and engraved or cut… and when I pull the masking off it’s pulling up the color as well. Which leads me to think that it is just sitting on top and not really staining the wood.

It’s expensive stuff, and so is the PG. I’ve been buying the PG, in part, because of the already applied masking. A large roll of that stuff is expensive! I just wish it came unfinished.

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Yah sanding hasnt worked well for me neither…I use mostly watercolors for my artwork and had to find another method with the use of paintpens. You can always buy adhesive backing from 3m and and non proofgrade wood to use the stains. I asked them to hopper unfinished maple when I was going through the same…hopefully one of these days​:blush::hugs:

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I don’t think you are going to get very good results but go with the highest grit you can put your hands on.
The veneer is quite thin and you will sand right through it if not careful.

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Depending on what you’re doing, a roll of masking is a bargain compared to the cost of PG.

Especially considering that you have to remove all that finish and get spotty results, the economics of the situation probably lean pretty heavily toward getting non PG stuff and masking.

If you sit down and do the math, I bet it wouldn’t take long for savings from non pg materials to far outweigh the time savings and wasted materials of doing it the way you’re doing now. It definitely worked out that way for me.

100 yard roll of masking is about 35 bucks. All you have to do is figure out the price differential between the non PG material you want versus the PG stuff (cost per square foot is probably the way to go here). Then you can take the difference and do the math to get a square footage that is your break even threshold.

I am definitely skimming over a few considerations:
Time to learn the materials (determining non PG settings is easy but does take time. luckily you have to do it “once”.)
Time saved removing PG finish and redoing items that fail your quality standard
Time lost to masking the material yourself (again not too hard, but does take time)
Shipping cost differentials
Depending on the material… reliability. Ambrosia maple is inherently inconsistent, for example, so you’ll see a lot of partial cuts. Some off-brand plywoods can be difficult and inconsistent, etc. – Unreliable materials can represent a considerable time cost.

Anyway, in my experience, non PG material cost is so much lower that it made my choice easy. Worth considering.

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The masking in large rolls was about 30 cent a board last I looked. Added to a 4x8 sized down makes it all rather low cost. But that is not your issue.

Glue and stain both can both be an issue with Proofgrade.
It is a great finish, until you want it gone.

I wonder if an argument for one sided or no finish is worthwhile?
I do not use a lot of Proofgrade, so no real skin in the game either way.

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I came up to about $0.25 usd per square foot (double sided masking), so yeah 30 per board isn’t a bad estimate.

For baltic birch (which I get for about $1 for a 12x20" board) you can see how the material savings just completely drowns out the masking cost.

Hardwoods are a mixed bag on cost, it’s a broad topic, so if we knew a specific species we could probably analyze it, but for now, the pain of removing the finish is probably worth the cost differential even if unfinished is slightly more expensive.

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I think you’d be so much better off buying the raw wood from Home Depot etc and having them cut it down. Even if the cost ended up being the same overall as PG material, the time saved with sanding would make it worth it.

FWIW, I’ve had good results with this stuff, but there’s other good ones out there.

https://www.amazon.com/gp/product/B017UREP4W/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1

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This is all good advice, … But what to do with the huge stack of proofgrade I already have? Is there any hope for good sanding results?

except the PG hardwoods are pretty limited. walnut, cherry, oak, basswood, poplar, maple. if you want something other than that (and the list is pretty long for options), it’s not going to be PG.

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Use it for projects that lend themselves better to :proofgrade:. Proofgrade has its merits. Last night I spent 15 minutes using a utility knife to free stuff from 3/16" birch plywood. The laser cut through over 99% of the length of the cut lines. That still left tiny little spots where I had to finish the process with a utility knife. I spent most of last weekend sanding, staining and applying polyacrylic to sheets of plywood in hotter than balls weather. Monday night I masked them. Proofgrade really isn’t an option for what I’m making, but in my moments of weakness I thought, they need to offer proofgrade in colors (and yes I know about the wood gallery’s colored plywood - still not what I need.) because I really don’t care about my money.

I’m sure you’ll eventually find projects where proofgrade is the best option.

I did sand off the finish on some proofgrade hardwood soon after I received my glowforge. I was doing inlays and needed to sand everything flush, plus the inlay parts weren’t finished. I used 120 grit to remove the finish and then 220 prior to refinishing. I did not use any stain. Have you tried your unicorn spit on a regular old piece of sanded wood and then apply masking and peel it off? Stain pretty much just sits on top of the wood. It should not pull up with a masking tape, but that is the first thing I would try in troubleshooting this problem.

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PG has a very thin veneer layer. I would attempt to chemically strip the wood before I would sand it. The PG is finished without stain, so you should get the natural wood color once the finish is removed. If you aren’t getting the finish completely removed, your additional finish layers will not be able to penetrate the wood fibers and will not adhere.

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mmm, Stripper… I hadn’t considered stripper.

"Have you tried your unicorn spit on a regular old piece of sanded wood and then apply masking and peel it off? "

Another good suggestion for troubleshooting.

That’s why I love this place. The Hive Mind.

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ZOMG, now I have to try that stuff! Curious how (if?) it will work with leather…

As to your original question, I’m going to echo the advice that others have given: I think you’ll see better results and use less effort to begin with an unfinished wood. Save the PG for other projects where it can shine, and where using pre-finished wood will actually save you time.

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That stuff is … every bit as magical as it seems… as for how it works with leather… I’m about to test that today. I’ll upload a pic.

People put it on fabric, wood, you can use a chalk primer and put it on anything. It stains wood and fabric but washes off your fingers like a breeze. It’s safe for kids to use. It’s super vibrant.

There is a bit of a learning curve (It’s water based, you have to use an oil or poly sealer). It can reactivate with water until it’s sealed. It’s super forgiving… but depending on the look you want, I recommend finding a tutorial to start.

The story is amazing too… Michelle, the inventor… she developed it in her work with disabled/senior adults… giving them something better to do than simple arts and crafts. Her brother ran an adult day care center. They loved it. Couldn’t get enough of it.

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Oh, please do! I just researched it a bit, and (as you mentioned) the stuff is not cheap. Would be nice to get a little preview before I invest :wink:

That makes me love it even more! I’m a firm believer in the notion that art heals.

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Do you have a special place that you get your 12x20 birch for $1.00 or is is something that you can share the location.

Not super special.

Rugby building products. $14 and change for a 60x60” sheet, which cuts perfectly into 15 12x20’s. Sadly rugby doesn’t cut it down, unlike my previous supplier. Hopefully I can find another supplier because cutting the sheet goods down is a major hassle.

More info here:

The general idea is to find a local supplier and see if they’ll cut it down for you.

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Thank you for your help

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@lizabeta

FYI, As some have commented. The PG finish is really durable and not easy to sand and when you do its very easy to blow right though the veneer and not notice it until you apply stain and get blotches. But if you must I recommend you use a wood scraper to get rid of most of the finish before sanding. But this will get expensive trying to get the results you desire. Also be aware that any chemical stripper you apply could also affect the glue bond of the veneer and the mdf core with undesired results.

For a more practical result search for other ply that is unfinished and you can achieve the results you desire. Yes it adds steps and in the end your cost might be similar or more than PF but it will be a much more stress free situation. If you live near a Menards I really love their maple ply for situations like this. Just be aware that you need to sand the ply on both sides prior to applying masking otherwise it peels easily during lasering. But you can apply stain and finish prior to masking and or afterwards as well.

https://www.menards.com/main/building-materials/panel-products/hardwood-panels/1-4-x-4-x-8-b4-natural-maple-mdf-core-plywood/14x4x8b4maplemdf/p-1444445023123-c-13334.htm?tid=-7814650570732605314&ipos=3

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