Finishing walnut table with pores(grain)

[Keith Harrell]

I just finished a coffee table made of walnut and have noticed more open pores this time in the wood. I have heard using tung oil and sanding can fill the pores but thought I would check first before i mess up and have to sand the top again.

Second question. Does linseed oil turn a little yellow after time? I build a plant stand with grow light and it seems to have pickup a tint of yellow now.

Thanks

[David Christopher]

Keith, I would use a grain filler...its fairly easy to use and it does a great job

something like this
http://woodworker.com/natural-por-o-pac-mssu-843-826.asp?utm_source=google&utm_medium=feed

[Prashun Patel]

I just finished a coffee table made of walnut and have noticed more open pores this time in the wood. I have heard using tung oil and sanding can fill the pores but thought I would check first before i mess up and have to sand the top again.


Tung oil and sanding is not a good idea because tung oil can remain soft in the pores.

The fastest is to use a pore filler - which contains thick solids intended for this purpose. However, applying this product in either oil or water base does involve a little bit of skill.

The second way is to do what you say above, with a varnish product. Wet sand it in with 220 or 320 grit. Push it into the grain. While it's wet, wipe at 45 degrees to the grain with a squeegie or soft cloth. Let dry. Repeat until the grain is filled - usually several coats are required.

The third way is to brush on a 3# cut of shellac, let it dry and to sand it back to the pores. Keep doing it until the pores are filled.

You shld really let the sfc cure if you do the latter 2 methods, to allow any shrinking of the finish to reveal itself.

[Lee Schierer]

Walnut will sun bleach under UV light to a light brown color. Many finishes also will turn yellow under UV light. Your plant grow light puts out a high level of UV light so some yellowing would be expected. Most interior grades of finish do not have UV inhibitors in them. Most exterior grade finishes do. You can use an exterior grade product indoors, but can't use an interior grade product outdoors without problems.

[Joe Chritz]

The light will expedite the natural color changes of the wood to a large degree.

The shellac filling trick is a very good on on woods with less pronounced pores. Walnut is fine to use shellac with. I usually spray a heavy coat but brushing is probably better. Let dry and sand back. Keep doing this until it is fully flat. You will see that by the shellac becoming uniformly dull when sanded.

Joe

[Keith Harrell]

I have been playing with some filler today I found.
One is natural and the other is brown.

Testing on scraps at this time.
The natural or white one leave white in the pores but it hasn't dried yet.
The brown seems to be good but again hasn't dried yet. I think I feel safer with the brown if I go that route.
What grit sandpaper is used if I try the shellac route. It' sanded to 320 now. I think I like the shellac idea at this time

Question 2
It sounds like the uv may be the issue which I didn't consider when I put the finish on. I'll tell her to buy more plants to cover the top

Sorry about this not being in the finishing forum

[Prashun Patel]

The pore filler you have should dry fast (within 10 mins) if it's oil based and even faster if it's waterbased. I haven't used waterbased. When using oil based, I squeegie it around, then use burlap to get it off. It's just like grouting tiles on a microscopic level!

If using shellac, I'd use a grit like 180-220. You really are sanding back all of the finish except for what's in the pores. The finer grits are only used when you're trying NOT to sand off the finish - just the dust nibs.

What's yr topcoat? If it's a film-forming type (lacquer/varnish) then sanding to 320 is overkill anyway. The only time I'd go north of 220 is if the finish is oil-varnish / soft finishes - like on the rocker you did.

[Frank Drew]

Shellac is a good finish for filling the pores on walnut, which could be considered semi-open pored compared to either mahogany or oak, but obviously not as closed pored as cherry.

Tung oil won't remain soft in the pores indefinitely, but it's a good idea to give each coat a couple of days to fully cure before applying a next coat. A good tung oil finish is, in my experience, very nice looking and quite durable; I've got table and dresser tops that must be nearing twenty years old showing very little signs of wear to the finish. In general, though, I'd prefer varnish or lacquer (if you're set up) for a flat surface.