Author Topic: Osmo unevenness  (Read 1037 times)

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Offline mrFinpgh

  • Posts: 217
Osmo unevenness
« on: July 14, 2017, 11:20 PM »
I've been doing some cabinet doors using Osmo Polyx and for the most part, they are turning out very well.  I like the application, and the feel of the finish is great.

Occasionally, there appear to be some 'dry spots' on the doors when viewed from certain angles.   I've attached a few photographs of what I'm referring to. These spots don't seem to follow a consistent pattern, and are present even after the second coat.

For my part, I've been sanding everything to 220, and filling the fronts of the doors with a water based grain filler (timbermate).  Then I am resanding at 220 with both a Rotary sander and finishing up with the grain by hand with a mirka block.

I've been using a white abrasive pad to apply the OSMO and have been diligent about 1) using a raking light and 2) applying extremely sparingly.   I am applying the OSMO in a pattern similar to a french polish.  Once I have worked the oil into every part of the surface, I finish with strokes going with the grain.  Finally, I am removing any excess with a shop towel, until the surface looks more 'buffed' than 'wet'. 

From most angles, everything looks great and the feel is wonderful.  But, as the photos illustrate, there are spots where the wood looks 'dry', even though I've carefully applied material to these areas.  Those dry spots are not visible from every angle, and sometimes a spot that looks 'dry' will look fine from another perspective.   

Hoping someone can offer some insight into what could be going on here.  I'm sure my grain filling job could have been better, but I also know there are areas with filled grain that don't demonstrate this issue.   I'm wondering if the finish somehow wasn't fully emulsified when I applied it?

Thanks,
Adam


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Offline mopo

  • Posts: 16
Re: Osmo unevenness
« Reply #1 on: July 15, 2017, 12:48 AM »
It almost looks like the spot is a patch of glue that's preventing oil absorption.

Offline Peter Parfitt

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Re: Osmo unevenness
« Reply #2 on: July 15, 2017, 01:28 AM »
Hi Adam

First of all, your description of the method that you used tells me that you have used a near perfect approach to putting the Osmo on.

From the pictures it looks as though the Osmo has not got into the grain in the area that you show. But could it be that you moved the board just before the Osmo was dry enough to handle?

Osmo is great for local repairs and so there should be no need to re-do the whole board. In the area of the fault just lightly sand, and I mean kiss the surface, to remove any high spots. Then apply, as before, a single coat in that area using the white pad. This time put a bit of pressure on the pad. Wipe off as before.

Additional coats dry more quickly than the first coat. and your board should be good within 12-24 hours.

As general advice, with Osmo there is no need to sand down to really fine grits. 220 is more than enough and I usually stop at 180. The first coat can take well over 24 hours to go off but subsequent coats dry much more quickly.

I am sitting close to my keyboard cabinet which has a tiny bit of a similar imperfection as yours. Mine is due to a very open grain veneer (which I did not use any grain filler on) and is something that I will live with until I have time to sort it out.

Good luck.

Peter

Offline mrFinpgh

  • Posts: 217
Re: Osmo unevenness
« Reply #3 on: July 20, 2017, 07:29 PM »
It almost looks like the spot is a patch of glue that's preventing oil absorption.

Thanks.  I looked at that, but there's no glue on those spots.   I have some other spots where there is glue and it looks a bit more pronounced, and less dry.

-Adam

Offline mrFinpgh

  • Posts: 217
Re: Osmo unevenness
« Reply #4 on: July 20, 2017, 07:35 PM »
Hi Adam

First of all, your description of the method that you used tells me that you have used a near perfect approach to putting the Osmo on.

From the pictures it looks as though the Osmo has not got into the grain in the area that you show. But could it be that you moved the board just before the Osmo was dry enough to handle?


I thought this might be the issue - I was moving around 8 doors per sessions, and rotating them through because my lighting was ideal in one area only.   But two things suggest to me that's not the issue:
  • Some of the dry spots are in areas I wouldn't touch without intentionally doing so.
  • I did some tall bookcase sides and left them alone after finishing, and ran into the same issue.

Right now, my working theory is that using the hard pad on the rotex, it might be skimming over some low spots, and perhaps those areas are not getting sufficiently flattened out to be hit by the higher grits.  Perhaps they are 'thirstier' as a result?  I'm not sure my logic is sound, but I did switch to a medium pad for the back of the bookcases, so we'll see.


Osmo is great for local repairs and so there should be no need to re-do the whole board. In the area of the fault just lightly sand, and I mean kiss the surface, to remove any high spots. Then apply, as before, a single coat in that area using the white pad. This time put a bit of pressure on the pad. Wipe off as before.

Additional coats dry more quickly than the first coat. and your board should be good within 12-24 hours.

As general advice, with Osmo there is no need to sand down to really fine grits. 220 is more than enough and I usually stop at 180. The first coat can take well over 24 hours to go off but subsequent coats dry much more quickly.



I tested this on a couple spots and it seems to do the trick.   I just need to be careful about finding the spots so I don't keep using up applicator materials.   

The main reason I went to 220 is that I start at 150 in rotex mode, and it seems like if I just do 150-180, it isn't sufficient to make the larger scratches disappear.   I'm hesistant to drop down to 120, as it is rather thin veneer.  Probably well worth keeping in mind for the future, though.

Thanks,
Adam