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Pore filling during finishing
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Author:  dmorg57 [ Thu Aug 25, 2011 7:48 am ]
Post subject:  Pore filling during finishing
Hello All,

I am about 8 coats deep into a EM6000 finishing job, and it appears that I did a really poor job of pore filling the Madi Redwood headplate. Would you suggest a large drop fill program w/ thickened finish, or do you think that I should breakout the Zpoxy and fill the headplate over the finish and shoot more coats?

Thanks

Dave
Author:  Barry Daniels [ Thu Aug 25, 2011 8:06 am ]
Post subject:  Re: Pore filling during finishing
Not a good idea to use epoxy in the middle of your finish application schedule. Drop filling the pores would take a lot of time and will tend to cause a few problems of its own, so I wouldn't recommend it. Drop fills with EM6000 don't always blend in perfectly and can come back to haunt you.

At this point, the best option is to just keep applying finish and sanding back. You will get to a flat finish after a few more coats, hopefully.
Author:  Stuart Gort [ Thu Aug 25, 2011 11:20 am ]
Post subject:  Re: Pore filling during finishing
The "Robin Method" might help here. :)

Robin is a furniture guy that gave me some finishing tips long ago. I'ved used this method for helping situations exactly as you described.

Let the previous coat(s) harden enough to sand without clogging.
Use 320 grit dry under a semi-flexible pad.
Make small circular motions to build up a dust layer in a 6" x 6" area.
Do not disturb the pristine dust layer. Particles of nitro dust are now helping to fill those pore recesses.
Spray another coat of nitro over the dust layer. It will burn into itself and fill a little as it goes.

It won't fill completely in one attempt, depending on the remaining pore recess depth...but it certainly fills faster than successive coats of nitro will.

Listen to others with more experience than I....but this has worked for me.
Author:  Barry Daniels [ Thu Aug 25, 2011 11:55 am ]
Post subject:  Re: Pore filling during finishing
Stuart, that may or may not work with EM6000. It does burn in, but I am not sure it would melt the sanding dust.
Author:  Stuart Gort [ Thu Aug 25, 2011 3:36 pm ]
Post subject:  Re: Pore filling during finishing
Barry Daniels wrote:
Stuart, that may or may not work with EM6000. It does burn in, but I am not sure it would melt the sanding dust.


That's a good point but Target Coatings, the company that makes EM6000, does say that it will burn into itself without sanding at any point. They further emphasized this to me on the phone as well. Typical nitrocellulose lacquer manufactures do not make the claim that you can spray over fully cured material and get that burn-in. Rather they tell you to sand between coats if more than a few hours have passed between coats. Logic tells me that if the "Robin Method" works with nitro, then it ought to work even better with a product that emphasizes the burn-in properties of their stuff. All that said....I haven't tried it with EM 6000 so there's that caviat. You are right to call me on that. This method will absolutely not work with polyesters, epoxies, and urethane finishes. Or...if it works at all it will likely cloud the finish.

Worst case in this scenario is that dmorg57 would have to sand down a layer of finish and resume topcoating from that point....which alone would mitigate his pore issue. If there is any problem with adhesion using the "Robin Method" I believe it would show up as a failure to clear within an hour of doing the coat. When you spread out the dust it is quite opaque. When you hit it with the topcoat it clears instantly. With EM 6000 there can be a tad of moisture trapped in the finish which shows as a bluish haze and usually clears out before an hour's time. If after an hour you see a clear finish...there is no adhesion issue and you are looking at one homogenous, strata free layer of film.

I would add that since EM 6000 requires many, many more coats to achieve any final finishing spec than conventional lacquers....it may be quite frustrating to simply try to add more coats to fix a pore preparation issue. If the "Robin Method" works with EM 6000 it will most certainly reduce the risk of laying down 15 or 20 coats only to see pore depressions that might not level out.
Author:  Ken Franklin [ Fri Aug 26, 2011 3:32 am ]
Post subject:  Re: Pore filling during finishing
First let me say that I have never tried this method with waterborne finishes but it should work. Worst case scenario you can sand it off as Todd suggests. Fill the pores with medium viscosity CA applied with a latex glove. You can sand lightly with 320 first if you like but it probably isn't necessary. One or two thin coats should do it. Then level sand and keep going with your original finish. I do this all the time with my rosettes and sometimes with the whole guitar. I like the non-fuming or foam safe CA from the local hobby store.
Author:  dmorg57 [ Fri Aug 26, 2011 7:53 am ]
Post subject:  Re: Pore filling during finishing
Thanks for the replys folks. I was hoping that I could fill midstream, but I believe that since it is such a relatively small area, I will hit it w/ the RO and start from the beginning. I am however going to try the Robin method on some scrap to see what the result is.

Cheers,

Dave
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