What if I sanded through the varnish?


Ronn W

Recommended Posts

So let's just say that this is hypothetical......

Just say that I had one coat of poly applied to a flat surface am and doing my "betweeen coat" sanding (by hand) and, after wiping the dust away I have some shiny, low spots that I would like to get rid of.  I figure that I could be a little more aggressive with the sanding to decrease the depth of the low spots so the next coat has a better chance of levelling them out.  What if....in the process, I sanded throught the one coat to bare wood in a couple of spots.  If I then apply a second coat of poly, will the area that was sanded through be visible???

Link to comment
Share on other sites

Just now, Ronn W said:

So let's just say that this is hypothetical......

Just say that I had one coat of poly applied to a flat surface am and doing my "betweeen coat" sanding (by hand) and, after wiping the dust away I have some shiny, low spots that I would like to get rid of.  I figure that I could be a little more aggressive with the sanding to decrease the depth of the low spots so the next coat has a better chance of levelling them out.  What if....in the process, I sanded throught the one coat to bare wood in a couple of spots.  If I then apply a second coat of poly, will the area that was sanded through be visible???

It should not be very noticeable on the first coat, gone after that. 

Link to comment
Share on other sites

I would thin the first coat to go down a bit more than usual to help it flow and level well. 

Between coat sanding shouldn't really be a sanding. Unless there are problem spots like your low shiney spots. If I get them, and I'm using a film forming finish, I will make the call if the next two levels will fill our not. If you did your prep well, they shouldn't be too deep and film finishes do build. 

Link to comment
Share on other sites

I will often put 2 thin coats on before sanding just to avoid the ease of sanding through.  I scuff those low spots with a gray abrasive pad. Corners and narrow edges only get the gray pad. Sanding always stops just shy of any edge or corner.

Vacuuming & wiping up every little speck of dust before the next coat is crucial.  I use microfiber cloths with great caution because any rough areas can snag fibers so tiny they only show up when your applying the next coat. Cotton tee shirt rags don't pick up the super fine dust but they don't leave tiny fibers......

  • Like 1
Link to comment
Share on other sites

I have given low areas a couple spot treatment coats then follow with a full coat. I sand those areas with 320 -400 grit and a cork block to feather out the perimeter before the next coat. Make sure any area with a thicker layer of finish is completely dried.  I always finish scraps alongside each project. Same sanding & prep as the project .The scrap is the last thing to get a coat. I only test the scrap for dryness, fingerprints don't matter there.

Of course I spray a sanding sealer that dries in 30-45 minutes and it sands beautifully after an hour. Still have to be cautious of sand through. Once I achieve a smooth flat surface I only use the gray abrasive pad and the cork block to scuff between coats . Same techniques apply to most types of finishes. 

Link to comment
Share on other sites

Bandsaw blade backwards with the motor direction reversed would cut in an upwards direction so the table would need to be flipped 180' .....that's where the idea falls apart.  I had a long day and after a couple drinks that's how my twisted mind saw the logical progression of trying to make a bandsaw work with the blade on backwards. 

My grandfather was helping me build a bedroom in the basement so I could have a waterbed when I was a teen. He grabbed my fathers drill and was trying to drill studs for wiring. The spade bit wouldn't cut . He looked at it and declared they had sharpened the bit backwards, walked over to the grinder and reversed the bevels then went back to drilling the studs .He had never seen a reversable drill .

  • Like 1
  • Haha 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Who's Online   0 Members, 0 Anonymous, 41 Guests (See full list)

    • There are no registered users currently online
  • Forum Statistics

    31.2k
    Total Topics
    421.7k
    Total Posts
  • Member Statistics

    23,756
    Total Members
    3,644
    Most Online
    FaithMoody
    Newest Member
    FaithMoody
    Joined