Cracks appeared after Organoil hard burnishing oil used

[slab2000]

Hi, this is my first post so please excuse any etiquette violations :-)

I've been an epoxy resin followed by varnish man for all of my projects but wanted to give the natural look a go. Organoil hard burnishing oil looked good on some trials and has worked a treat on a stringy bark slab. I'm really happy with the finish, but noticed some hairline cracks have opened up a bit, to the point where I'm a bit concerned about water ingress. The cracks 'appeared' as I worked on the finish. Now, am I being too anal because I am used to sealing everything up with resin, or is this an issue I should worry about? The slab will be a bench in a laundry, so a wet area but minimally so.

Thanks in anticipation
Anth

[ian]

how dry is your slab?

was it cut a long time ago or more recently and is still losing moisture ?

[LGS]

What kind of timber is the slab? Some pictures might help if you can get some. There is one thing that might cause this phenomenon. If you have applied excess oil, then it will begin to seep out of the wood about 3-5 days after you have finished the piece.

If this is what you are seeing, then it isn't a problem. A number of users, including myself, have had this happen. Here's what I did.

1. Wipe the wood down with a dry cotton cloth until most of the surface oil is removed from the surface.
2. Get some cheap paper serviettes ((the ones from Macca's work a treat) and use these in place of a sandpaper pad on the ROS to remove the excess oil, just by doing the same thing you did to apply the oil
3 Repeat the ROS wiping several times, until the wood begins to take on the sheen that it developed previously.
4 This may take several "wipes" with the ROS to achieve.
5 The oil then dries very well and I have had no issues with the wood since. It's waterproof and heat resistant as ever.

The oiling process takes a little getting used to, but I think it's worth it. DO NOT believe that the oil has failed. You just need to get used to it, same as most good oil finishes.

Another couple of tips.

1. When you apply the oil, directions encouraged to saturate the timber with oil until the surface is truly soaked before sanding. You don't need that much. Add the oil after the 400 grit, then let it sit until the oil has all soaked in.
if it is saturated after one application, you could probably stop then. If you need to add more, be a little reserved with the next coat. The piece is ready to be burnished when the surface is shiny but not dripping wet. I use 400, 800 1200,1500,2000 and 4000 grit with the oil. And of course, give the timber a good wipe down at the end. It my be good to get yourself some practice pieces and see how it goes. By the sound of it, you're nearly there.

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This is about how I like the surface to look after oiling, but before burnishing. The oil is clearly evident, but the timber isn't drowning in it.

Here's another tip.

1. You can happily use "Spray and Wipe" on the dry oil to remove dirt and other build up. After the cleaner dries, you'll have the same lustrous shine.


Regards,

Rob

[slab2000]

Was cut a long time ago, around the same time as other slabs I've worked on where this didn't happen.

[slab2000]

Thanks for the details Rob. I've read some of your posts on the topic and was led by that and the online instructions from Organoil. I don't think there was excess oil on the surface but I wonder if excess oil made it into the cracks. I've looked at pre-oiling photos and can see some hairline cracks, so I should correct myself and say that the cracks opened up rather than 'appeared'. That might have been obvious anyway. The slab is from a recovered spotted gum and has been dried. I've successfully applied the oil to a stringybark without problem. I've included some photos, a few wide shots and a close up of some cracks that have opened up. I'll keep an eye on moisture over the next few days and follow your instructions above.

From the photos, do you think the cracks are wide enough to want to do something about? I've always filled cracks with epoxy resin in the past, does the burnishing process keep the cracks from widening or will they cause a problem down the track, do you think?

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[slab2000]

The close ups don't show the cracks too clearly, the widest one is maybe just wide enough to slip a piece of paper into...

[LGS]

When you hard burnish the oil into the timber, you should develop a slurry, which will become a filler as you continue through the higher grits. This should fill the fine cracks that are present. At 4000 you shouldn't have a problem with visible cracks. The final wipe down will show only the great result you've already got.


Regards,

Rob

[slab2000]

Thanks Rob, it sounds like the problem was that I moved through the lower grit pads too quickly. I found that I had more control of the slurry when I practised by hand so I'll go back to a lower grit and re-do, this time by hand, at least at lower grits. It might be a while but I'll try to post a final pic.

[slab2000]

Thanks for your help Rob, I re-burnished and spent more time on lower grits, plus left the sanding dust on the bench. I also worked mostly by hand which gave me more control. The cracks filled perfectly and except for a few larger ones you cannot see them. I am stoked with the result and even with doing it twice it took a fraction of the time compared to resin, sanding and varnish. I've attached a few finals pics.

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