Replies

1. 
   SteveSchoene | Feb 20, 2010 04:18pm | #1

   I'm not sure what you mean by
   I'm not sure what you mean by wanting the finish to be "reversible", and why that is important. NC Lacquer is a a notch more alcohol resistant than shellac but not really in the high durability class when it comes to solvents, and moisture.

   Otherwise, I would be thinking about a oil bssed varnisn which does resist cleaners, alcohol, and moisture quite well.

1. 
   Westchester | Feb 20, 2010 05:49pm | #2

   Finishes are reversible by stripping them off - just make sure you use finishes that are made for furniture -

   You will have an easier time with the lacquer if you use retarder. 

   Mohawk Finishing products is a mail order Co. for finishing products - they also have good instruction for application of their products -

   SA

2. 
   cahudson42 | Feb 20, 2010 06:26pm | #3

   Thanks Steve,

   Sorry to be unclear - by 'reversible' I meant that the finish could easily be dissolved off and removed, reflowed, or otherwise  redone in case of damage etc.

   I've finished earlier cherry small table top pieces (I,e Shaker Candlestand) with Danish Oil/wiping varnish - and while they initially looked great, wife continues to put wet glasses on them, and they now have water damage rings. Since the finish was 'catalytic' I can't redissolve it - like with laquer or shellac. I have to steel wool it, sand it, strip it.  (Or? Suggestions?).  Why not sand etc?? Over the years, the cherry now has a beautiful, deep 'oxblood' patina. If I sand - likely that will be destroyed.

   Yes, I could use a poly - but I did a maple table in that - and while it doesn't have water rings, it looks like plastic.

   So this time, I'm looking for a very easy to repair cherry finish so that when it too gets damaged with water, catsup, mustard, booze, knife cuts, heat etc.. I can easily repair it without losing the patina. (Its a 'Butler's Table' - and this is going to happen...)

   Chris

   P.S - I do use thinned wiped-on 'Marine'  phenolic varnish on my Adirondack chairs/outdoor furniture  - and it works just fine

   D

1. 
   DonStephan | Feb 21, 2010 12:12pm | #5

   What was the composition of the catalyzed wiping varnish that developed water rings?  Might it have been a water borne acrylic product or was it a solvent varnish?

   I don't think any easily repaired finish will be durable - sounds like competing objectives.  If you want to use nitrocellulose lacquer, Mohawk sells padding lacquer and similar products to repair the finish.  You might even be able to build a new finish with enough applications, but I'm not familiar with that product.

   If you can find a supplier (Woodcraft is one) you might experiment with Tried and True Varnish on some scrap and wet glasses.

1. 
   cahudson42 | Feb 21, 2010 05:41pm | #7

   Thanks Don,

   With yours and Steves comments above - I took a shot at repairing the water rings (ref response above under Steves initial comment).

   To answer your question, I am pretty sure the finish was/is Watco Danish Oil.

   FWIW - I will never, ever use a water borne acrylic product.  Many, many years ago I worked as a Lab Tech for a supplier of latex (acrylic) paints in their Research Lab in NJ. We spent all our time trying to balance durability/water resistance against the need to add 'surfactants' (soaps) to keep the resin in suspension. Obviously, the more 'soap' the easier the finish dissolved - rather re-dissolved - when water hit it. It will take a very good argument to convince me that 'water and oil can mix' - and that any water-borne finish can ever approach a similar-resined solvent-based finish.

   hris

1. 
   DonStephan | Feb 21, 2010 06:36pm | #8

   FWW #207 Oct 2009 has an article pp 51-55 on wipe-on finishes.  It suggests Danish Oil has only moderate water resistance.  Sounds like wiping varnish has pretty good water resistance.  You might find the article interesting.

2. 
   cahudson42 | Feb 20, 2010 09:14pm | #4

   How about you chemists out there?

   A lacquer 'pullover' concoction can only 'slightly' dissolve the laquer.  (Nitrocellulose). The very top surface.

   Possibilities:

   A 'carrier' that does not dissolve the lacquer at all, with a small percentage - of say - something that does? MEK? (Naptha + MEK?  Mineral sprits + MEK?)

   What ratios? 90% ms/naptha/10% MEK? 80%? or?

   Ideas to try?

3. 
   cahudson42 | Feb 21, 2010 05:27pm | #6

   RE: Water Rings

   Thanks Steve,

   The water-ringed candlestick table was - I think - finished with Watco Danish oil. It was one of my first projects -  maybe 3 years ago - and its 90% chance that is what it is.

   Based on your suggestion, I took a little Turpentine (no Ethanol handy right now) and a small pad of 0000 steel wool. Rigs are gone, and patina is not damaged! I then wiped on a little more Watco - and wiped it off. Looks like new! Except deep patina was retained!

   Unfortunately, I did this 'in place' in the LR while wife was napping - and now I'm hearing the smell is going to kill her Parakeet. Oh Well..  Table is at least fixed - for now.

   Thanks again!

   Chris

4. 
   cahudson42 | Mar 02, 2010 03:54pm | #9

   Thanks to help from our great Editors Asa Christiana and Mark Schoefield at FWW, I now have some Mylands Pullovever Solvent  'on the way'.

   Mark spoke with Jack Davis, of Davis Enterprises, the US distributor for Mylands. Turns out that while they don't list the Lacquer Pullover Solvent  on their US website, they do keep a little on hand.

   While Davis usually sells wholesale,  he courteously offered to sell me some - 500 ml for about $10 plus $7 shipping.

   He is at   888 369 5263  Call with a credit card and he might  send you a can if its on hand, or perhaps point you to someone who carries it retail.

   I'll report on a new thread how well it worked out for me - likely in a good few weeks.

1. 
   cahudson42 | Mar 07, 2010 10:33am | #11

   Couldn't find much info on lacquer pullover technique either - let alone what it is. But here is an excerpt from a interesting lengthy post on the Australian Woodwork Forum: (full Post at: http://www.woodworkforums.com/f9/spraying-lacquer-19490/ )

   By 'Durwood":

   "4) Don't forget air hits the timber before the lacquer gets there so if the grain shows holes when you spray you will be hard pressed to fill them. One of the reasons lacquer was so popular is because of its ability to be "pulled" or treated like french polishing. If you cut with wet paper like a car painted does you get white sludge which is hard to clean away. If you make a pad using a piece of fair dinkum chammois with cotton wool inside to rub the lacquer after its final coat (let it dry completely -24 hrs) you can soften any dry spray or orange peel and move it into the grain holes. As the lacquer drys so fast you just work your way over the area when its gets too soft move on and come back later.

   To do this mix 50% [lacquer] thinner and 50% metho [Australian for Ethyl Alcohol - Ethanol. NOT methanol as you might think]  adjust the mixture up or down to suit your needs metho weakens the action ot the thinner making it possible to rub the surface and move around the lacquer. Add the mix from the back of the pad wetting the cotton wool and squeezing it through to the front of the chammois. don't have it dripping but the chammios must be wet. Rub in circles, then in figure eights and then straight lines. If you ever wondered how they get grand piano's so good this is how.

   You should be able to get a mirror finish, but some people like to pull the lacquer and then spray a flow coat of thinner/clear -90/10 to finish. Pulling over is really good on odd surfaces such as turned legs and other odd shapes.

   About actually spraying, wide open fan ( long thin oval) thats like a wide paint brush. less chance of runs. If you close the fan all that paint gets stuffed into a smaller area so you will get runs. Hold the gun about a hand span away and at 90Degree to the surface move at a rate of about a metre in four seconds if you move faster you need to open the fluid control for more, if you go slower close it. you won't get a run if you keep the gun moving and keep the didstance the same. always pull the trigger before surface and don't stop till you get pass the other end. start at the top of vertical surfaces and work down.

   Over lap about a quarter of the fan width each time you do the next pass,

   On edges spray moving the gun just as you would on a big surface, every second you are onto a dry area, if you go vertically you have to cover the length of the fan to hit dry surface, turn the air cap across ways to do vertical painting of tilt the gun at an angle to you use the narrow part of the fan."

   Waiting for weather to warm a bit to try all this..:>)  Have to finish outside  :>(

5. 
   AZMO | Mar 02, 2010 11:30pm | #10

   You might send Old Dusty a note, he is the king of spray finish work. Based on his input, I have completed some tops in NC Laquer. I have found that using retarder at about 30% ratio allows it to spread and film better. When first sprayed it has an orange peel look but dries pretty flat. I use a card scaper to level the tops after every second layer, and a quick sand between. Seems to work for me here in AZ, but different temps and humidity might be different. I use Simpsons laquer by the way. Post a pic when you can.

   AZMO