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Lockwoodsman
1st September 2010, 12:00 AM
G'day fine folks,
Apologies if this should have been a new psot as opposed to a threaad - I figure it lives under "finishing etc, so here goes....

I'm after some advice as to the process and/or experience any of you may have had regarding how fine to dry sand before applying a danish oil then wetsanding onto a redgum tabletop. At this stage I've completed the 600 grit with a ROS with a view to wetsanding to 800 then 1200 (both by hand). The last 2 stages (800, 1200) I was sanding the oil into the top to create a slurry followed by wipe off. After my 600 grit stage (where I'm at now), I've since read that I may have gone too fine with the 600 as this may impede the capacity of the 100+ aged redgum to take the oil on. This leaves me with the issue of 1: Should I go back through a grade or two to get back to a 320 or 400 prior to oil application, and 2: When I wet sand, how many grades would one recommend to go finer after the say 320 or 400 grade I was left with prior to oil application. Looks a muddle this threead I know, but any advice would be very helpful. Cheers
LWM

mic-d
1st September 2010, 08:54 AM
Hi LWM,
Sand to 220, apply first coat of oil as a flood coat and keep wet for 5 minutes if any dry spots appear, then wipe off excess. allow to cure o/night then sand any roughness to 280. Apply subsequent coats and sand dust nibs with 400 after each cures. Wet sand the last coat with 600 *

*source Understanding Wood Finishing. How to select and apply the right finish, Bob Flexner 1999.

Cheers
Michael

Wizened of Oz
1st September 2010, 03:28 PM
Have you oiled redgum before? Best you try out on a scrap first to see if you like the result. Oil makes some dark red timbers look like mud.

LGS
1st September 2010, 06:01 PM
Hi LWN,

I have used Wattyl Scandinavian oil and Organoil Hard Burnishing Oil on Red Gum with great success. I usually dry sand to 400g then flood with oil, allow the oil to soak in for about 15-30 minutes then wet sand from 400g to 4000g.
I don't see that resanding to 400 down from 600 should be necessary, but you may want to wet sand using the 600g you used previously, then 800, 1200 and 1500 using a ROS. If you are using a 150mm ROS pad, you might like to get yourself a couple of 2000 and 4000 Festool Platin 2 discs. These have no holes in them and can be used to great effect. Also, I find that wiping down the workpiece with Mineral Turps after you finish dry sanding gets rid of grease and sawdust very well.
Here's some pics to show you.

pic #1 Red Gum ashes urn
pic #2 and #3. Jarrah box with a red gum top panel.
Both done with Wattyl Scandinavian oil as detailed above.

Superbunny
1st September 2010, 09:18 PM
:aro-u: I guess that says it all with proof of the results.:D:D

SB

Skew ChiDAMN!!
2nd September 2010, 01:29 AM
:whs:

I've found that what grit I stop at depends on the wood. I tend to test sand an off-cut with a sanding block along the grain before I use each grit.

When I can't see the difference between that and the last grit - ie. the grit is finer than the coarseness of the timber's grain - I know it's time to apply the finish.

This can be anywhere between 240 & 480 grit... depending on the wood. To my mind further dry sanding with finer grits is pointless, even with a ROS.

The first wet sand fills in the grain and, once dry, the surface is flatter and finer grits make a real difference.

(Or such is my understanding of the process. Admittedly, I use pure Tung Oil but Danish is the same method; it's just not as laborious in building up thickness of coats.)

gdayj
23rd September 2010, 06:09 PM
anyone got a favourite brand / type of paper for wet sanding??

Lockwoodsman
6th June 2012, 04:04 PM
Thanks to the folks that posted on this link. I'm rapt to inform the few of you that I've finally finished the table (check out the snaps). Much appreciation must go to you guys for your assistance. many hours of hard yakka (7 coats on the top - 5 on the frame and 3 underneath) produced what i reckon to be a pretty handy result. The thing outta last!