Finishing questions

[transatlantic]

I'm working on applying the finish to a project made from pine. The finish I am trying to achieve is silky smooth with no gloss or shine. I sanded down to 240 and applied a coat of Liberon Finishing oil. As per the instructions, I applied sparingly and wiped off the remaining after 10 minutes. I repeated this 3 times, rubbing with 0000 wire wool between coats. I'm not happy with the result though

- It doesn't feel smooth, but a kind of sticky feeling, even though the oil is dry. Your hand doesnt brush along the surface smoothly, there is friction.
- The grain has risen causing small contours on the surface
- The wire wool has left grey dirty marks in many places
- It's quite glossy/shiny

So I thought perhaps the wire wool was too much of a high grit, and I've heard people say they sand down with 240 between coats. I tried this (by hand) (with the grain) and now there are clear scratch patterns

so yeah - bit of a balls up. I guess I'll have to sand it by down with 120 and start again! .. no problem though, it's a learning exerience! (and it gives me a chance to remove glue smudges that I missed)

Questions :

1) Advice on the above?
2) I was wiping down with old socks to remove the excess (I don't have any lint free cloths), and applying with a foam brush. Both of which are unusable the second time around. What is a more cost effective approach for this? how should I clean the foam brush? .. can I use something like tissue or kitchen roll for removing the excess? or are they too "gritty"
3) How can I deal with the grain rising issue? It's not all over, just on the darker ring bits

 

[Keithie]

It says 5 hours between coats and while I dont really know, it is pretty cold at this time of year so I'd be leaving it a fair bit more than that (like one coat per day ...but thats me!) If sticky it says to cut back with white spirits.

As for the grain standing up, I would have sanded down much further and do so in all directions (tho I always go ott on sanding) ...but then that wouldnt be in line with Liberon instructions and would make it more difficult for the oil to penetrate, this time and every successive year when you re-apply.

I use 'blue' paper roll for applying liquid finishes and wiping off excess

I'm sure someone who does things properly and knows what they're doing will be along to give better advice!

 

[profchris]

Pine is a problem because it's really soft, and the pale wood is softer than the darker streaks.

I made a banjo uke neck from Pine as an experiment, and applied several coats of blonde shellac, sanding back between coats. Eventually this gave me a hard enough surface so that I got something like you describe (then I applied TruOil on top to get a gloss).

240 grit is too coarse here - I used P1000 Abranet, so maybe the equivalent in grit sandpaper. Must have been 8+ coats, and these were needed just to get a surface I could sand really smooth.

How about satin varnish? This coats much thicker, so probably two coats and you can sand smooth, then a couple more for your final finish?

 

[woodpig]

I'd try cellulose sanding sealer cut back with an abrasive pad or 0000 wire wool.

 

[Phil Pascoe]

^^ as above. Three coats to mind is not enough to get a finish, although you'll get a matt finish quicker than a gloss one. If you are leaving dirty marks it would suggest to me that the oil is not dry, only touch dry - two different things. If you don't choose to use cellulose s/s you could wipe it down with hot water and allow it to dry before sanding. If it does no good it'll do no harm.

 

[transatlantic]

Ah ok. Perhaps it wasn't as dry as I thought then. It was left for around 36 hours, but it has been cold. Will bring into house I think this time.

I have some sanding sealer I think.

So :

- Sand off all the existing oil with 120
- Sand back up to 320 (120 -> 180 -> 240 -> 320)
- Apply Sanding sealer, cut back with 320?
- Apply at least 3 coats of finishing oil, 320 inbetween?
- Sand back with 600 or so to get it back to Matt? (I'm trying to get a very matt finish)

 

[Phil Pascoe]

If you've sanded and cleaned off properly you shouldn't need to do it between every coat, the oil is quite thin and every second or third coat is enough. You can work this in with your working pattern - if a coat isn't 100% dry in a few hours but touch dry, so long as it hasn't picked up any dust or nibs you can recoat then leave for a few days to dry fully. I tend to use Danish rather than Finishing Oil but they are much the same to use, and I've found it best to leave the item for a couple of weeks after the last coat before flatting if matt is desired. If there is the slightest drag on your paper (I use 0000 steel wool) it isn't dry.

 

[transatlantic]

Wait no, I can't bring it indoors to dry as I have birds. How long do you think this would take to dry fully outside (garage) in this cold weather?

 

[Phil Pascoe]

I would leave it a few days at least, and we're a bit warmer than you.

 

[profchris]

And the normal rule with oil finishes is that you must get your surface as perfectly smooth as you need before applying - the oil won't fill imperfections, even highlights them. So you might want multiple sanding sealer coats and sanding before you apply the oil.

This will help because your sanding sealer should dry much faster than oil, and you can then leave the oil to cure fully before you do the final sanding back to matt. Currently around 0 C in Suffolk, and forecast to be like this until into next week, so you could seal and sand over the weekend, first coat of oil Sunday, then leave as long as it needs.

 

[transatlantic]

Righto. When I sand between the sand sealer coasts, I assume they're going to very very thin? .. so should it be a very light sanding by hand? or can I use a random orbital sander (which I find gives me a cleaner result)?

 

[profchris]

I'd try hand sanding with a hard block. Any give means the soft grain gets sanded more than the hard (darker).

 

[bracspin]

I use Liberon finishing oil on much of what I make in hardwood (cannot comment on softwood). The first coat tends to dry in around 3 hours as it absorbs quickly. I then apply a second coat and leave it for at least six hours or until it feels firm. When happy I will gently wipe with a 000 wire wool. On my final coat I try to do it in the evening so it has overnight to dry. Another gentle wipe with 000 wire wool completes the process. If it is in a cold environment then I would suggest adding 2 hours to each of the procceses. A quick touch will tell you if it is right. When right it gives a lovely finish.