Sanding before or after acid?

[plainpainter 217]

Other than the deck I posted about the befores and 16 month afters - I usually end up sanding my decks down. I like it better that way - perhaps it's a better job - and perhaps folks in New England neglect their decks much much more than the rest of the nation - and we have really harsh elements here. Anyways - I got to thinking - if I put on an alkaline stripper followed by an acid bath - then sand. Then potentially aren't I sanding off the top layer of 'conditioned' wood? I mean - if you sand wood enough it becomes 'clean' but wood has 'stuff' in it that may or may not interact with stains. And a brightener seems a good way of sequestering that stuff out of the top layer.

So what I want to know - has anyone experimented with sanding after the stripping stage but before the acid/brightening stage? And did you notice any different results? The more I think about it - it introduces more days on the job and less profitability - but It seemed to me that it may be a superior job - who knows?

[Mountain View 14]

I can't see how you would gain any better results doing things in that order, except reduce your profit and extend the time for doing the job.

[Beth n Rod 1,279]

Good question Daniel,

I have asked myself that very question but then the first time I tried to sand without washing all the crap off first was an indicator on a larger scale what I would be up against and I didn't like the prospect.

The mold and mildew makes for some quick clogging of the sandpaper.

Now, I realize that doing the job right the first time is key but sometimes one just needs to do it twice as the second time is purely just for the removal of all the dirt and debris from the sanding process and ensuring the surface is properly prepped.

Wash/strip/neutralize the wood, sand, then wash the wood again with a percarbonate/neutralize, buff then seal.

Works like a charm.

Some may consider this to be reducing profits but that is an assumption. The pricing has to be in line with the work in order to keep it profitable.

Obviously this is calculated accordingly. The following is for those who are curious...

Wash/Strip/Neutralize= $xxx (sqft)

Sanding= $xxx (sqft/hr+materials and rental)

Percarb wash= $xxx (sqft-% [for less difficulty])

Buffing= $xxx

Seal = $xxx

Yes, we do get customers to pay for all this, they are willing to do so because the potential of having it reskinned vs sanding is more expensive.

The motivator is small children and alleviation of splinters for all.

Rod!~

Edited December 6, 2008 by Beth n Rod
Grammar

[plainpainter 217]

Thanks for your insight, Rod. I wasn't thinking about sanding the mildew - I was first assuming the stripping part - then come back after deck is stripped - then sand - then neutralize. I see you have a percarb cleaning in your second 'washing' steps.

What I would like to know - you say 'wash/strip/neutralize' - do you say 'wash' as a formality? Or do you actually wash a deck before stripping? I've always just gone ahead and stripped decks - sometimes I put a bleach solution if there is real thick stuff that would get in the way of stripping - but rarely.

And I have an even greater question. Reading some of Rick Petry's postings I have this sequence a try a couple of times.

Strip/percarb-wash/brighten. I don't know if it was a better job - it seems that stripping does the cleaning for the most part anyways - of perhaps I am getting lazy? I guess each deck is different - but under a blanket of water - and it's already 2pm - who wants to really make up a batch of percarb cleaner - if the wood looks good?

[Beth n Rod 1,279]

The

Wash/strip/neutralize

is a relative statement pertaining to whatever step is necessary on any particular job. No I don't strip then wash or vice versa. The one exception was a time that I washed a golf course type deck...algae had become moss! It was so thick I had to hit it with a bleach and sodium hydroxide mix first just to kill it off and wash it to remove the mess. Then I proceeded to strip the deck then neutralize afterwards. oh, I forgot about the foot deep layer of leaves I had to blow off first to even see the deck!

It wasn't one of my prouder deck jobs because the deck never sees the light of day due to the terrain and the tree coverage. The customer wasn't interested in having it sanded to help make the floor look any better which was severely neglected, had tons of planters and a cat that used it as a part time litter box.

Rod!~

Edited December 6, 2008 by Beth n Rod
additional comments

[Beth n Rod 1,279]

The day you sand an active sap vein will be another day you have fun with clogged sand paper.... ;)

Beth

[plainpainter 217]

The day you sand an active sap vein will be another day you have fun with clogged sand paper.... ;)

Beth

I've noticed on my own work - where I sanded down the deckboards alot - even if it's 15-20 yr. old deck boards. They become 'active' again with sap. I've got lots of areas of whiteness now on my decks where sap has been coming to the surface - some decks look worse after my restoration than before sometimes. And I've never really found a good system of removing sap other than hitting it with a scrubber and VM&P naptha.

[Beth n Rod 1,279]

Sorry I this is going a little off topic, but if the sap is coming out again or has been seeping, the best suggestion I have is board replacement. Obvious I know but the sap can continue exuding for a couple of years till the vein is depleted.

Back on topic :winkanim:

Rod!~

Edited December 7, 2008 by Beth n Rod

[MudDuck 20]

Rod maybe I'm missing it but you wash (precarb or just blow it off?) strip / neutralize / sand / then precarb and neutralize wash again? I have always just stripped / neutralize / sand n blow off dust w/ leaf blower / seal...Your precarbing and neutralizing a second time?

[Beth n Rod 1,279]

Not always but in certain cases. Sometime we do it the way you have listed, other times not. Depends on the job.

Beth

[PressurePros 249]

I could achieve utter perfection in any job whether it be a house wash, a deck job or cleaning and selaing a strip of concrete. Two things preclude me from adapting a policy of perfection. Profitability and customer satisfaction.

The profitability needs little explaination. There would be too much diminishing return in the time spent trying to upsell three and four trips to a single job site and/or the time spent achieving perfection. ie. I could probably push the ultimate restoration on a deck but would customers pay $1800 (not counting carpentry) to have a 12'x20' deck restored when in one year it would look markedly faded and in two years it could look crappy again? Would I be setting a precedence of perfection that would not lend itself to just maintenance cleaning and restaining every couple of years?

The customer satisfaction angle is one some contractors don't have a grasp upon. People are not paying for a pressure washing job. They are paying for the benefits that come from it. Yes, a customer wants a good job and may even believe they want perfection but they are not willing to pay for it. In an exterior environment, its silly to even ask them to pay for it. Dan, even in an interior paint job, there will be flaws revealed if someone sticks their nose 6" from the surface. People also want little inconvenience. The very nature of having a contractor on their property is an inconvenience. Having to keep their furniture off the deck while the stain cures is an inconvenience. Prolonging that inconvenience can hurt you more than it can help your sale.

I have added sanding all deck floors as part of my service. After doing this (deck work) for awhile, I have noticed a big difference in decks that were sanded.. a more even finish and better penetration of sealer. To set nails and sand the average deck adds maybe an hour to the job. I've settled on adding $.15 per s.f to my base pricing to keep it profitable. If you are using a good surfactant with your acid, it will pentrate farther into the wood than sanding will remove. So first trip is clean and pH balance and second trip is sand, blow and stain.

[MMI Enterprises 289]

So first trip is clean and pH balance and second trip is sand, blow and stain.

Have to totally agree here..unless it's real hot out then sand or defur can also happen first trip.

I have added sanding all deck floors as part of my service.

I've noticed it can be expected as that is what has been pushed or talked about the most in respect to refinishing a deck. Buyer don't care if it is more labor intensive or less profitable by way of being an extra step in a wash methodology. Some apparently think it is the best and only step involved and are leery of washer method even being involved.

And I've never really found a good system of removing sap other than hitting it with a scrubber and VM&P naptha.

Hows that wrok out compared to say turpentine? Edited December 7, 2008 by MMI Enterprises

[plainpainter 217]

So first trip is clean and pH balance and second trip is sand, blow and stain.

Ken - this is exactly how I am doing things now. I had one of those infamous re-lapses of 'technician' thinking. I thank you for doing a virtual 'bonking' on my noodle to set me straight. I have to keep the bigger picture in mind, which is customer satisfaction balanced with time management and profitability. Perhaps what I said would be a better job - but your are right - it's academic at this point - and as well certainly not good enough to make ipe stain jobs last 3-4 years before a maintenance coat.

But let me ask you one last question - I am a minimalist when it comes to the acid/brightening step. If apply with a pump up - I apply a fine mist - which I mix 4 ozs. of oxalic per gallon. If I downstream copious amounts of solution - my end mix is 2ozs gallon. I am not the 6 and 8 ozs that I see other guys using. So here comes the question....If I am going to sand wood - should I perhaps go back to the stronger dilutions recommended by the manufacterers of 8-9 ozs. per gallon - to make sure of a more even sequestering deeper into the wood? So I am still left with ample 'treated' wood after sanding?

[MMI Enterprises 289]

Dan, I don't get it.. you surely set up with good DS system and have access to bulk acid. Why you not just drench them decks quik and easy? With the redwood I sometimes hit with a second lighter application right as it almost becomes dry as sometimes the alkalines or extractives leach up or move around and sometimes show an area as a tad darker. Think this transpires due to fact I usually do first application while wood is good and wet with main rinse and it allows acid to really get in deep. I would ask you does the deck do an immediate flip flop to lite color when using a light pump up application? I like to know that when I am leaving a job that when I return it will have still been benefitting from brightening procedure for awhile due to getting it deep enough.... Main thing my pump-ups carry is extra strength stripper for spot work or laq for stamped crete.

In my opinion, a rewetting of a sanded or defurred deck is only going to risk raising grain hence allowing for some uneven staining.

Edited December 7, 2008 by MMI Enterprises

[plainpainter 217]

Kevin - I was just showing what I do whether it is downstreaming or pump-up. Big jobs I usually downstream acid - my main quesition is to the strength of the acid. I tried Bob's oxalic at 9ozs. per gallon in a pump up sprayer and was horrified at how bleached out white the deck became - so I have been a 'minimalist' ever since - why use more if you don't have to? My acid applications don't do an instantaneous bounce like you say - they're very much gradual and I let the acid dwell for 15+ minutes.

And sometimes I don't take my whole trailer rig out. This year I was looking to save money - so sometimes I took a 7hp pressure washer into my van and used a pump sprayer for some of the smaller deck jobs. I realized I was extrememly fast - but I figured what was the point of hauling my tandem axle trailer for $700 jobs start to finish? So sometimes I 'downsized' and I have different application rates when I use a pump up vs. my downstreamer.

[plainpainter 217]

Kevin VM&P naptha is much stronger, I think, than turpentine. Turpentine is strong and certainly stronger than all the grades of mineral spirits, except a couple. But VM&P naptha is what I like to use to hit really hardened sap that needs to be emulsified - without being ridiculously cancer causing like toluene or acetone, which are even stronger than VM&P naptha.

[James 625]

One issue here is most people Neutralize when the wood is to wet . So your only affecting the surface of the wood. Second issue is Cedar or Redwood are the woods with the most problems concerning Tannins and I've had occasions to have to Neut a couple of times because of tannins. Hardwoods are a pain too concerning finish removal and Blackness that looks like Tannins but it's not. It's a whole other issue ?

[MMI Enterprises 289]

See everyone may look at things different... Like perhaps James means to imply that since the wood is already wet and pores occupied that the acid can't get in hence the 'too wet' statement. Think he also means, as did I, that it allows for tannins' etc. to move around. Is similar when carpets are cleaned and left too wet.. ya get a whick back effect of any dirt or chems left behind. In such case of carpets this makes for a dirty look or a resoiling issue due to sticky chems.

But on the wood I picture it that when you have an amount of water/chemical needing neutralized it doesn't matter as far as wood being wet already. Whether pores or occupied space in general the applied acid will find it's way in to all parts of what is already wet and mix to point of neitralizing just as if it was an open container with straight liquid. It's gonna happen, it's gonna mix without stratifying or some such because it is the same solvent in the form of water. So in my mind 'too wet' only applies to the tannins/extractives, or left over chems moving around.

[MMI Enterprises 289]

Kevin VM&P naptha is much stronger, I think, than turpentine.

Does that really hold true though what with the organic nature of sap and turps?

[plainpainter 217]

Kevin - turps were used to make Damar varnish - which is a resin from a pine tree - so yes you can use turps. It's just VM&P naptha will get the job done quicker - and there is nothing I can stand worse is fooling around with sap veins - especially when I never bid for the extra work!

[Beth n Rod 1,279]

Rod maybe I'm missing it but you wash (precarb or just blow it off?) strip / neutralize / sand / then precarb and neutralize wash again? I have always just stripped / neutralize / sand n blow off dust w/ leaf blower / seal...Your precarbing and neutralizing a second time?

Correct!

This is not for every sanding job, but there are times more often than not that the deck gets dirty from not only the sawdust but tracks from mud, scuffs from boots and people sweat a lot.

I don't know if any of you have noticed but the sweat alone on a deck can leave little spots with a whitish haze the customer is always pointing out.

Besides, the percarb helps to also take a second whack at the crud in the cracks the sanding and blower does not remove.

Rod!~

[Beth n Rod 1,279]

Correct!

This is not for every sanding job, but there are times more often than not that the deck gets dirty from not only the sawdust but tracks from mud, scuffs from boots and people sweat a lot.

I don't know if any of you have noticed but the sweat alone on a deck can leave little spots with a whitish haze the customer is always pointing out.

Besides, the percarb helps to also take a second whack at the crud in the cracks the sanding and blower does not remove.

Rod!~

Exactly. A cookie cutter approach is NOT necessarily the correct one. Look at the job site and the job and decide from there.

Beth

[plainpainter 217]

But I want a cookie cutter approach!

[James 625]

I think this thread is getting out of context. The only time you will have too do multi- Neutralization and re-cleaning is for difficult jobs that call for it. Which Rod has stated and I haven't even touched upon things I've done.

[MMI Enterprises 289]

Which Rod has stated and I haven't even touched upon things I've done.

Well yea we now know Rod sweats alot on decks..lol..What things you done on a deck that top that?...hehe :)

[fireandrain 39]

I second Jim's comments re: tannins and redwood... I always neutralize 2nd time after sanding. I skipped it on a deck this year and the deck darkened up in all the areas where we spot sanded before sealing. Looked like crap. Fortunately, HO's were thrilled with th overall transformation and didnt sweat the darker areas. I wasn't happy at all though.