Fix a finish

[RCBill 14]

Last summer I attempted to restore my deck. I write attempted because the results are unacceptable. The color is uneven.

In the begining.... the deck was in terrible shape, UV damage, dry, and cracked. I replaced a lot of wood. I got it washed pretty well, removing dead wood, and learning to use the Osbourne brush. So far, pretty good. I'm ready for the Ready Seal Lt. Brown. I apply two layers as instructed to less then spectacular results; some of the wood is near black, some is brown as expected, and the new wood is another brown. I understand why the new and old wood would absorb different amounts of stain. And I understand that being a painter and all, that I would have challenges with exterior wood.

None-the-less, I need to learn a few things from this.

1. Is very UV damaged wood a poor application for a transparent stain?

2. When I need to replace wood, should I look for something other than a transparent stain.

3. Can anything be done with the existing stain to even the color?

TIA,

And Happy Easter,

Bill

[RPetry 564]

Bill,

A few questions. What is the wood, cedar, pressure treated, something else? Was there an old stain(s) in the wood prior to cleaning? What chemicals did you use to clean the wood? Did you follow up the cleaning with an oxalic or citric neutralizer/brightener?

Prior to applying the Ready Seal, did you use a moisture meter to test the dryness of the wood? How many gallons of Ready Seal did you use on ~ how many sq. feet of wood? In the deck exposed to a lot of sun?

Aside from cedar, I find the Ready Seal light brown too light in color for most decks, especially those with a lot of sun exposure and/or wilth old, beat up wood. A medium brown or medium red selection may be a better choice.

[RCBill 14]

Rick,

The wood is PTP.

I cleaned with EFC-38, then bleach.

As I recall, I applied Oxalic after the 38.

I don't think that I would be able to state with any kind of accuracy how much material I put on. I believe I put the first layer on about as heavy as the wood would allow and most likely did the same with the second. I did not allow puddles.

The deck gets a lot of sun.

I have a moisture meter and while I do not recall measuring the wood, I do not think that applying stain to wet wood would be a mistake that I would make. Lot of wood in that last sentence.

About parafinic oils;

Do parafinic oils contain parafin? Isn't this wax? Isn't wax difficult to coat with good adhesion?

Do most 'Woodies' use parafinic oils exclusively?

I see that Wood Defender offers a semi-transparent fence stain, but not a semi-transparent deck stain. What could the limitations be?

Thanks,

Bill

[RCBill 14]

The picture of the deck was shortly after I stained it. Much of the color has disappated.

The cracked board was typical of what I moved into.

I cannot post new pictures until I purchase new software.

Bill

[seymore 90]

Parrafin oil is a petrolium base product that is a penetrating oil.

Yes i ONLY use an oil base stain on all my work..:cool:

If you want to email me your pictures i can shrink them and resend to you .

seymore1024@gmail.com

[seymore 90]

Bill you could just apply more RS stain to to the wood since it was old wood .It just need to get more pigment into the wood.Then the deck may look more uniform in color.You might want to test some area applying more stain abd see how it looks

[RPetry 564]

Bill,

As far as the original prep to the wood last year, that is a suite of chems I have never tried. EFC-38 alone should have cleaned the wood, with oxalic after to brighten. Not sure if the bleach mix in between was needed or may have caused a problem. Oxalic after bleach is not, from what I can determine, a good idea.

Was the wood wetted with water before applying the bleach mix? Was the bleach mix rinsed very, very well out of the wood before the oxalic?

I use Ready Seal exclusively for PT, cedar, redwood, etc. One thing I have learned is that a moisture meter is imperative. The wood may look dry and feel dry, but still not at or less than 12%. Not just on the surface of the wood, the wood maybe 1/4" deep must be at or below that moisture level. Sink the pins of the meter down into the wood to get a proper reading.

1. Is very UV damaged wood a poor application for a transparent stain?

IMO, no. I've use RS on some very nasty, old wood with good results. But the first application will take a large amount of stain. The thing about good parafinnic oil stains is that they penetrate into the old beat up wood and replace lost natural oils and resins, helping to give the wood a new lease on life.

2. When I need to replace wood, should I look for something other than a transparent stain.

IMO, no. Why would that be?

3. Can anything be done with the existing stain to even the color?

Yes. I would do a very light, VERY LOW pressure cleaning of the existing stain with a ~2% bleach mix and a small amount of detergent soap. Rinse well. DO NOT follow up with any acid bath. Sink the pins of your moisture meter into the wood to make sure its at 12% or less before applying the RS.

With the age and condition of the PT wood, as well as full sun exposure, IMO the light brown is a bad choice. Go with at least a medium brown or medium red. You can apply a darker RS over the existing light brown without any problem. These colors have a lot more pigment, as Shane mentioned.

And as you know, use plenty or oil! You will get that old wood looking good again.

[jnoden 15]

wood defender does have a semi trans deck stain. I just started using wood defender this year. re-check the web site for standard paints and you will see the deck stain.

[RCBill 14]

What happens when the wood has not been nuetralized correctly?

I will check on the semi-trans deck stain. I used the semi for fences to great results.

[Littlefield 65]

Not neutralizing after stripping will yield darker wood, with tannins being drawn up to the surface and left there. Also, the stain may fail quicker due to .....drumroll........saponification. A cleaning agent reacting with the oil based stain in an attempt to convert it to soap.

Saponification is the hydrolysis of an ester under basic conditions to form an alcohol and the salt of the acid. Saponification is commonly used to refer to the reaction of a metallic alkali (base) with a fat or oil to form soap.

CH2-OOC-R - CH-OOC-R - CH2-OOC-R (fat) + 3 NaOH ( or KOH) both heated →

CH2-OH -CH-OH - CH2-OH (glycerol) + 3 R-CO2-Na (soap) R=(CH2)14CH3 (for example) Lye is a form of sodium hydroxide (NaOH) which is a caustic base. If NaOH is used a hard soap is formed, whereas a soft soap is formed when potassium hydroxide (KOH) is used.

Vegetable oils and animal fats are fatty esters in the form of triacylglycerols. The alkali breaks the ester bond and releases the fatty acid and glycerol.

The soap is salted out by precipitating it with saturated sodium chloride.

[RCBill 14]

Rich,

I understand the first paragraph. Just curious, what language was that for the second?

I sense that having a firm grasp of the interaction of the chems and stains that we're using is gonna be pretty important (oops, comedy doesn't transmit well in this medium), so I need to ask a few things.

What would a finish that is failing due to poor or omitted nuetralizing look like?

How fast might a stain begin to fail?

Do I understand you correctly in that the caustic cleaning agent will go after the stain? What does it do to it?

I think of three, maybe four, different wood cleaning agents, bleach, Percarb, a Percarb with other agents like EFC-38 (I guess each of those added chems is an agent), and Sodium Hydroxide. Is each caustic enough to require nuetralizing?

Shane, do you nuetralize da bleach?

Am I spelling nuetralize correctly?

Bill

[big mike 14]

From looking at your pictures, it would appear that the wood you're working with is extremely neglected and UV damaged. Thus, the recommended 2 coats are going to soak into that wood really deep. This will happen gradually and pull the pigment in the Ready Seal with it. When I run into these type of decks, I plan on several coats over a period of a couple weeks, to get the lumber replentished with oil. I would recommend 2 additional coats of Ready Seal. The first being clear, to replentish that thirsty deck, followed by a coat of the light brown. Improper neutralization will show up rather quickly, and usually appears as spotting or blotchy areas.

[Beth n Rod 1,279]

My take on it from the first pic appears that not all of the previous sealer was removed. The steps show a stain still present lending to the problem. Strip it, neutralize and reapply. At this point you may also need to defur the wood as well. We find that by defurring in addition to the above steps brings the wood to a condition that shows the sealer better than if this step is omitted.

Rod!~

ps...good one Rich. Haven't heard that term since we did our hood exhaust cleaning certification.