Reddit mentions of 3M Sandblaster 20320-G-4, 9" x 11", 320 Grit, Sandpaper, 4 Pack

Edit: Before you read, these two pieces of wood started the same. The one on the left is the "bad" version based on how I used to finish things.



I'm absolutely no finishing expert, but I've spent the past couple of months getting ready to finish a major project. I have used a lot of shellac and other varnishes in the past, but generally like oil-based poly. Here's now I do it.


This advice probably applies to all woods, but I've been working with Walnut and Maple recently.

1. Strongly consider filling the grain. If you want a glass-smooth surface, you have to fill the grain.
   
   
2. Get the table nice and flat and sand to 220 before anything on top.
   
   
   
3. Put some boiled linseed oil or tung oil on. Let dry for 2-3 days (maybe more). Sand very lightly with 320. Repeat 3-6 times. Let dry for a week after the final coat. Sand to 320 again.
   
   
   
4. Cut your oil based poly 2:1 with mineral spirits.
   
   
   
5. Brush it on very very slowly and smoothly with a good brush. Watch this video. https://www.youtube.com/watch?v=lb7SJl1A5q8 I use almost no pressure and just drag the rush very slowly. This prevents bubbles. Bubbles are your enemy. If you go fast, you'll have bubbles. Also, get a good brush. 2-3" ox hair finishing brush. Again, you aren't painting. You're laying down material. DON'T PAINT.
   
   
   
6. Ruin your work. This step is a big leap. Seriously, sand with 320 nice and flat before putting on the 2nd coat (see attached picture).
   
   
   
7. Put on more coats.
   
   
   
8. Before my last coat, I sand the base layer with 320, 400, and 600 so it's super flat. Then I put on a nice and thin top coat and dry for 2-3 days before polishing.
   
   
   
9. Sand with 400 on up to 3000. Buff with some wax. Done.
   
   
   http://i.imgur.com/ZywuN6X.jpg This is a bit of a bad example as I didn't fill the grain (and haven't really polished yet), but this shows why sanding matters. If you don't want ridges where the grain is, you have to sand. Again, not the best picture, but sanding and putting on thin coats, slowly, will get you the finish you want.
   
   
   I'm absolutely not an expert. Just someone that's been frustrated sharing what I've learned. Here's my latest table-top with coat #2 on it.
   
   http://i.imgur.com/DpqiIvO.jpg
   
   
   Finally, not all sandpaper is the same. For 320, this is the best stuff around. Lasts forever and doesn't clog: https://www.amazon.com/gp/product/B00PPD1CYA

• For containers I just use 1 pint cheap plastic containers that soups come in or deli give you. I guess you can find a nice piece of Tupperware that is about that size, and a taller one for taller prints. You could probly just ask the Deli guys at a food store for a few empty 1 pint containers + lids.
  
  
  • 2 containers - one with pure IPA and one with clean water. Good lids that won't leak.
    
    
• 91% or 99% IPA for cleaning your build plate / resin vat / scraping tools / desk / etc. and for using in the print wash container. https://www.amazon.com/gp/product/B01ABPUGH0/ref=oh_aui_detailpage_o06_s01?ie=UTF8&psc=1
  
  
• More gloves: https://www.amazon.com/gp/product/B00CF49NJS/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1 My palm width is about 3.6 inches / 9.2 cm and I bought the XL which fit ok.
  
  
• More paint strainers: https://www.amazon.com/gp/product/B01HQELZ7E/ref=oh_aui_detailpage_o08_s02?ie=UTF8&psc=1
  
  
• Better removal tools: https://www.amazon.com/gp/product/B01A81FXMK/ref=oh_aui_detailpage_o09_s00?ie=UTF8&psc=1
  
  
• Also get some Xacto knives + extra blades + sand paper sheets in varying grit 300-400 count for smoothing off support marks. https://www.amazon.com/X-Acto-XZ3601-X-ACTO-Knife-Safety/dp/B005KRSWM6/ref=sr_1_6?ie=UTF8&qid=1527015690&sr=8-6&keywords=xacto+blade
  
  Try to find the flexible sand paper sheets that are meant to be hand-used. I found them in Loews 3m brand, this is the exact type of sheets i use: https://www.amazon.com/3M-COMPANY-28320SB-UF4-320G-Sandpaper/dp/B00PPD1CYA/ref=sr_1_7?s=office-products&ie=UTF8&qid=1527015867&sr=8-7&keywords=sandpaper+320+grit+3m
  
  
• Find a source for cheap paper towels. I use the real cheap paper towels that you find in bathrooms, the stuff that's really stiff and crappy. I don't use name brands such as Bounty or whatever because the higher quality kitchen paper towels leave behind bits of cloth dust, which is unwanted for cleaning the resin vat / build plate / LCD screen. You'll also go through shitloads of paper towels and the higher quality towels are a waste of money. https://imgur.com/7XeelfV
  
  
• Get a couple sunglasses cleaning cloths. Not the microfiber cloths with the consistency of a bathroom towel: https://www.amazon.com/dp/B009L77OXE/ref=sspa_dk_detail_4?psc=1&pd_rd_i=B009L77OXE&pd_rd_wg=OcvWJ&pd_rd_r=3AAAFBB1202BXG3K8QN0&pd_rd_w=cwumx That's just an example - you can probly finder cheaper and better sized/quality towels such as: https://www.amazon.com/MagicFiber-Microfiber-Cleaning-Cloths-PACK/dp/B0050R67U0/ref=pd_bxgy_421_img_2?_encoding=UTF8&pd_rd_i=B0050R67U0&pd_rd_r=PR868R09NE2DQCC8NBVQ&pd_rd_w=0uPs5&pd_rd_wg=eAMNx&psc=1&refRID=PR868R09NE2DQCC8NBVQ
  
  I use these cloths on the LCD screen and the resin vat FEP sheet. After cleaning the resin vat FEP sheet and the LCD with paper towels, I give them a nice polish with the cleaning cloth to remove any other smudges or dust. Make sure to have a cloth dedicated to ONLY the LCD screen, as you want the keep the LCD screen pristine and free of dust and smudges.
  
  You'll also want a print curing station to harden the prints once they have been cleaned. I bought:
  
  
• A plastic cookie jar; clear plastic, round: https://www.bedbathandbeyond.com/store/product/oxo-good-grips-reg-3-piece-pop-canister-set/3262796?categoryId=12605
  
  
• UV LED Light Strip: https://www.amazon.com/gp/product/B075ZQZDBR/ref=oh_aui_detailpage_o08_s02?ie=UTF8&psc=1
  
  
• Heavy duty tape, such as duct tape or gorilla tape. I used black gorilla tape.
  
  
• Aluminum Foil
  
  

1. Wrap the LED strip around the plastic container to this effect: https://imgur.com/oB98Qxl . Make sure you wrap so that the power cable connector will be at the bottom of the container. Make sure you secure the beginning and the end of the LED strip to container with a piece of tape.
   
   
2. Wrap the LED'd container with aluminum foil - shiny side facing inward. Lay out a long piece of foil on the floor, shiny side facing up, just enough to cover the container's length once. Secure the beginning of the foil piece with a piece of tape, and then secure the end of the foil. Try to wrap without causing creases in the foil, keeping the foil as shiny and smooth as possible. Make sure your power cable plug in point is popping out and able to be plugged in.
   
   
3. Secure a piece of foil to the base, shiny side facing inward.
   
   
4. Secure a piece of foil to the lid, shiny side inward. Take a piece of tape and make a 2-sticky-sided loop to secure the foil. Make sure the foil is not interfering with the lid's ability to securely close.
   
   
5. Wrap the whole thing with your gorilla or duct tape. Make sure your power cable plug-in point is popping out and able to be plugged in.