Thoughts on Oxalic and Ipe

[plainpainter 217]

Russell among others sells a milder acid that contains citric acids - it's selling points being that it doesn't harshly bleach the wood like oxalic and it improves your spread rate - while I am inclined to agree, I had another thought swimming in my head of mine - the one that Ipe is a hard wood to get anything to stick too. Then in my head I did one of those 'one plus one is two' moments.

If oxalic 'opens' up the wood much more severely than a citric blend - wouldn't it make more sense to use that on a wood like Ipe - to clean out the 'pores' and get a better penetration of your stain, especially woodtux.

And I am not really interested in people talking about the 'integrity' of the wood - and how we are here to preserve it. I am talking about the top few mils. I mean come one - not one of us hesitates to sand down a few mils when confronted by a nasty restoration job. Can't we just all agree the top few mils is fair game when it comes to getting stain to adhere? I mean in an inch you got 1,000 mils to play with before you run out. Floor sanders wack out your hardwood floors after the 3rd sanding. What's the big deal about getting that top few mils cleaned out for better penetration of stain. A penetration that once in place will stop or put a great damper on wood decay and allow longevity of your wood.

[Beth n Rod 1,279]

If only the Atlantic City boardwalk could talk.

Never been there, is it made of Ipe'? ...or is that the old fly on the wall kinda speak?

Rod!~

[RPetry 564]

Rod,

I'm not sure of the complete AC boardwalk surface, but a large portion was replaced with ipe' about 30 years ago. It has never seen a finish. Not sure if they clean it periodically or not.

Now there would be a nice contract! Anyone here with political connections?

[plainpainter 217]

Rod - if you are entertaining the thought of offering a twice a year conditioning of ipe decks. Does this imply you would go over to a parafinnic stain instead of curing stain?

[Celeste 341]

I'm just now getting around to reading this thread and I'm kicking myself in the rear! Last March we purchased ipe decking tiles for our H&G booth floor. Knowing they were new and going to be stained, we gave them a bath with ESP Citralic, well, half of them. Mixed regular strength (6 oz) and the driveway went red. Yep, we flipped out. Okay, so, the rest got cleaned with about a 4oz mix - no red river. They all looked quite lovely when dry & stained. Here's where the kick in the pants comes in. Some of them have held their stain better than others and I DON'T KNOW WHICH ONES!!!! We had originally chalked it up to different boards (because we have hundreds of little boards attached together, not regular decking boards) but now I have to wonder if it was the strength of the mix that may have contributed.

If it ever warms up again here, we'll also jump in on this testing thing. Ours will be the tiles, stripped of their WTW, then we'll neutralize in various brews as well :) We can also put different stains on different tiles - have WTW, WR, RS & FPSP on hand. Let the testing begin again!

Celeste

[MMI Enterprises 289]

Well is this going to be pure oxalic & citric crystal at same percentage?

I have no experience with testing the two on ipe or how a stain would hold differently but from my tests on 20 year old fir and cedar on both spa and fence over the last year I can confirm that the oxalic removed the gray and calcium much faster and was better at showing the original natural wood color. I know it is aside from the tests your going to do concerning stain but isn't it pretty darn important to get to the point of a real even look let alone prior to leaving for a night of dry time of worrying about if stain/seal is going to look decent on it? I think the claim of differing spread ratio results is very possable but that it is likely to be more geared around incomplete removal or leach out in general of the dead stuff and rinse methods. I would like to see the staining results of 4 tests between the two acid with 2 of the tests using a garden hose fan rinse and the other 2 using just less then fur damage.

I'de almost bet that only one would be more prone to being able to scrape off a fingernail full of dead stuff that logic says changes the stain absorbtion.

[seymore 90]

Now there would be a nice contract! Anyone here with political connections?

Rick I'll call Tony Soprano for you and see what i can do? I have to make my waste managment payment this month ;)

[seymore 90]

I don't work on IPE but maby a few planter boxes.I don't see why there would be a difference between oxalic/citric?I use only oxalic but don't they do the samething to wood?Oxalic being stronger and works faster to brighten? The wood does look a little orange after oxalic.Does citric also make PT wood or cedar look orange?

Why would it matter if the wood is gonna look a shade different with oxalic or citric if you are gonna stain it anyway?? I can't tell the difference with bleach or oxalic after the wood is stained especially PT wood :D :cool:

[RPetry 564]

Kevin,

This is Daniel's experiment, I'm just supplying the ipe' deck. So he is in charge of protocol.

I am a bit confused with your rinsing statements. Are you talking about rinsing the oxalic and citric acids off the wood after dwelling? If so, you raise a procedure I had not considered.

Bear with me, I have never used oxalic acid on wood. For 5 years I have only used straight citric acid mixed at 6 oz./ gal. to brighten /neutralize strippers and percarb cleaners. And it never is rinsed off wood that will be stained with Ready Seal. Well, if it rains hard that night, but never on purpose.

Hey Daniel, help me out here. Am I suppose to rinse off this oxalic acid?

Shane,

Does citric also make PT wood or cedar look orange?

No, not at 6oz./gal. or else I'm color blind. Just brightens the wood to a "new" type look.

I'll call Tony Soprano for you and see what i can do? I have to make my waste managment payment this month

Not sure about Atlantic City but in some areas of NJ it use to be that way in some public bidding of contracts. Hopefully, not so prevalent today. Political connections may still be a big help.

At ACR last month they had a new machine that could probably clean the AC boardwalk ipe' in no time flat. It's made for concrete, so it would be perfect for cleaning ipe'!

[seymore 90]

Thanks Rick :cool:

Like i said having not worked on IPE that much but when i did and used bleach only.It got a little lighter but looked like new once stained.

I would think IPE is like working with New ACQ wood where nothing wants to soak in.So I'm with Jim and I would advise customers to let the wood turn grey.How ever long it takes if it's in the sun 100% or partial sun 6mths-1yr.I would tell the customer to wet the IPE down ever so often to speed up the aging.

Since bleach dries wood out so much wouldn't you want to wash IPE with a light bleach/soap mixture?

I've been trying to figure out what this thread is trying to accomplish??

[MMI Enterprises 289]

Seymore, I think he's trying to figure out if oxalic wood takes more stain and adhears different is all....

[seymore 90]

Seymore, I think he's trying to figure out if oxalic wood takes more stain and adhears different is all....

Ahhh he should be named Plainscientist not Plainpainter :D

If there is an experiment that should made it should be bleach vs oxalic.I would use oxalic if the wood had rust stains or leaf stains.

I still feel bleach will prep the wood up better to accept the stain.

[MMI Enterprises 289]

Rick, I say to rinse before the staining part. The two chems are likely to leave differing amounts of soft fiber that you can scrape off cause they likely burn different and deeper, and probably one keeps on burning with time or more sun. Oxalic gets whiter faster and more so on crete then the citric and I suspect it will have some similar effect on the wood along same lines when still active. If you stop the action of both by rinsing as well as you can then you can confirm more important things. Whether or not the wood became changed or any more porous deeper on in and would be immedietly seen by stain absorbtion. Leaving it on could say more about down the road effects of which might be better to rinse off prior to sealing..Is not my bag to leave a reaction happening unchecked on anything so I am out of line in speaking on this really. I would rather know which absorbs more after using a citric mix or an oxalic mix meant to be washed off cause they have cleaners in them and but this is apparently more about which to leave in the wood or not. I call a manufacture claim that one is worse then the other to use (clean with) is subjective to whether their product is going to be left on or not.

[MMI Enterprises 289]

Ahhh he should be named Plainscientist not Plainpainter :D

If there is an experiment that should made it should be bleach vs oxalic.I would use oxalic if the wood had rust stains or leaf stains.

I still feel bleach will prep the wood up better to accept the stain.

Irony has it that prior to seeing this thread this early afternoon I did just that but I did it with PC,TSP,apple blossom, and borax... is almost good enough to accept stain...lol

Oh and BTW, the amount of grey after a year was same on all boards.

[seymore 90]

Irony has it that prior to seeing this thread this early afternoon I did just that but I did it with PC,TSP,apple blossom, and borax... is almost good enough to accept stain...lol

Oh and BTW, the amount of grey after a year was same on all boards.

What's the PC?? with the TSP etc?

BlEaCh?

I haven't tried TSP in my mix cause it worries me if it gets on windows!

[MMI Enterprises 289]

Not sure yet what the tsp will do to windows at the ratio I did.

I did 8 oz. percarb, 3 oz tsp, .5 oz apple blossom, and .5 oz borax to 1 gal. and flojetted it on for a dwell of 15 minutes.. the reaction and cling was perfect for my taste. A very mild application of either acid after would be fine to make perfect for staining. That mix is almost same as 'apple sauce' for roofs but without the chlorine. It stripped aged acrylic floor finish just fine the other night...

I'll post up the ph level chart I was working on to the chemical section on how the two acids differ.. I see either as just as harmfull to fish along with ph being different.

[seymore 90]

Ahh PC=precarb...did it turn the wood dark?

I've never used it but i've heard it turns the wood dark. Since the IPE is SO bullet proof and rock hard why not use bleach/soap?

What if you have mildew deep in the wood and the prevarb doesn't remove it? Now you gonna have mildew coming up from under the stain.

I had that problem after stripping cedar and i only used stripper and oxalic.It looked great when wet but when i came back to stain it was all black and blotchy.Cleaned with bleach again then it was good to go.So it was a lesson i'll never let happen again. 1.strip 2. bleach RINSE RINSE 3. Oxalic

[Greg R 82]

Interesting topic.....

I wouldn't be surprised to see a color variation in the brightening as oxalic is a much stronger acid. I would be surprised to see any difference the the spread rates though. The strippers/cleaners are typically what pull the oils out of the wood. The acids to my knowledge should just be supressing the tanins in the wood and off-setting the alkaline ph closer to nuetral.

[John T 744]

For probably at least 5 yrs I only used a Citralic acid to neutralize/Brightened decks but for around the last 3 yrs I only been using Oxalic for this because it seems to make the wood brighter because of the stronger strength of the acid. Oxalic is a more dangerous acid to use but I always make sure I'm covered good and I wear my respirator. Oxalic is also cheaper for me to purchase where a 55lb bag cost me about a dollar a pound.

My thinking is since the Oxalic is a more caustic chemical then Citralic it probably penetrates deeper into the wood which may cause the stain to soak in a hair more in the IPE wood which might mean that you get a little more time before the deck turns grey. Either way Mahogany and IPE decks that are exposed to sun here never get two years of looking good with a sealer on them.

[plainpainter 217]

Rick - sorry to respond so latel, I had no idea this thread would cause such a commotion. But I would prefer it if you rinsed your acids after you let them dwell for a while - I'd say 15 or so minutes - howeve long you feel when the woods have brightedned to your satisifaction - but however long you allow the citric - allow the oxalic the same amount of time as well. I say this because once the acids gets on the wood it will react with the residual stripper/percarb/alkaline to form salts - and you should remove the majority of those salts - they can react with the finish as well.

Shane - I was once using oxalic acid to clean up some teak wood on a boat. What I noticed is that all this mildew that was all over this fiberglass boat surface was being washed away after being treated with the oxalic acid - so I have thought from that time on that oxalic is a decent mildew killer. But if you are having problems - why not after you strip/bleach - instead of following with oxalic - use bleach-stop - it is something like sodium thiosulfate - it is meant to neutralise bleach - and being an acid will also brighten and turn any remaining alkaline into salts - this I think would make your prep bulletproof - and nobody would be able critisize you for using bleach. Here is a link Bleach-Stop (Sodium Thiosulfate) - 3 lbs.

[Beth n Rod 1,279]

Rod - if you are entertaining the thought of offering a twice a year conditioning of ipe decks. Does this imply you would go over to a parafinnic stain instead of curing stain?

Not really, I like the curing stains performance over the paraffinic. Just a preference at this point and no logical argument to support it at this time other than to say I have more faith in them from our observations.

Rod!~

[RPetry 564]

Kevin,

Ok, Daniel concurs, its a rinse off of both the citric and oxalic acids. Both acids will get the same dwell time. Next question, which should be used first which will default to the control? Keep in mind that I have never used oxalic, but from what I understand it is quicker acting and more "harsh" in the sense of being "stronger", even though both will be mixed at 6 oz. /gal.

Start with the citric, time until the ipe' looks brightened, then rinse. Or start off and do the same with the oxalic? Does it matter? Again, I'll defer to Daniel on this, its his experiment.

You mentioned in a post above,

The two chems are likely to leave differing amounts of soft fiber that you can scrape off cause they likely burn different and deeper,

Is this an oxalic result? I've not noticed any "burning" or "soft fiber" remaining after citric acid use.

Anyway, two pics attached. The ipe' was cleaned with percarb, allowed to dry, and lightly sanded with 60 grit using a random orbital. No acids have been applied yet. First is a close up of the deck floor. Second is our test bed of 2 x 6 ipe' top rail running the length of the deck.

http://windsorwoodcare.com/images/bboard_photos/dscf0015.jpg

http://windsorwoodcare.com/images/bboard_photos/dscf0017.jpg

If you want to compare to original condition before cleaning, I posted 4 pics on the 2nd page of this thread.

[MMI Enterprises 289]

You mentioned in a post above,

Quote:

The two chems are likely to leave differing amounts of soft fiber that you can scrape off cause they likely burn different and deeper,

Is this an oxalic result? I've not noticed any "burning" or "soft fiber" remaining after citric acid use.

Anyway, two pics attached. The ipe' was cleaned with percarb, allowed to dry, and lightly sanded with 60 grit using a random orbital. No acids have been applied yet. First is a close up of the deck floor. Second is our test bed of 2 x 6 ipe' top rail running the length of the deck.

http://windsorwoodcare.com/images/bb...s/dscf0015.jpg

http://windsorwoodcare.com/images/bb...s/dscf0017.jpg

If you want to compare to original condition before cleaning, I posted 4 pics on the 2nd page of this thread.

Just ignore that cause your wood is already satisfactory far as cleaning the old dead grey mush off the surface. Your actually using the acids to brighten and to actually go from alkaline to acidic. Your not just neutralizing and are after the brightening aspects of the acid. I like what your doing in this cause it helps to control the myth of how one might clean better then the other.

Far as mold coming back I don't know for sure but imagine that pc is a good enough sanitizer that it won't survive. It isn't strong enough at the strength I used to disolve 1" algae like chlorine of the 'apple sauce' mix might but I think it dead enough. The tsp isn't something to shake a stick at either. Painters been using it forever prior to painting and I heard something over the years about it was used heavily in the whaling industry to bleach whale bones..??

But don't get me wrong as I am not advocating using it in the residentail HO market. I don't know sufficiently what it does to wood.(maybe an anchient deck hand on a whaler cound say or ma ladies flowers..time will tell)

..oh and no I got no darkening effects from the pc or rather the mix I used, only nice light original looking wood..

[RPetry 564]

Kevin,

You stated:

Your actually using the acids to brighten and to actually go from alkaline to acidic.

Yes. This is normal procedure with prepping exterior wood. Ah, with one caveat. I am guessing some exterior wood stains should not be applied on an acidic wood. Thus, the stain manufacturer may require a water rinsing of the acid neutralizer / brightener prior to applying the stain.

My normal process with Ready Seal stains is to apply the citric acid and either come back the next day or start staining shortly thereafter if it is a hardwood or a very sunny, warm, and dry day. No rinsing. Thus I guess I am just brightening the wood and acid'fying it, not neutralizing it. Did I just make up a new word?

[plainpainter 217]

Rick - the citric is the control, that's what you are use to using - use the citric first like you would normally do - then allow the same concentration of oxalic for the same amount of time - record all the times - and post pictures of what eveything looks like after neutralizing. But yeah - rinse - be sure to rinse. this will also be a test for you as whether to rinse or not from now on. Although don't rinse for all your customer decks for one season - wait til you see the results on your own deck before changing your own methods - but the majoritiy of us here like to rinse.

[RPetry 564]

Daniel,

Ok, the citric is the control. Will be timed for dwell and throughly rinsed. Same time and rinse for the oxalic. Both to be mixed 6 oz. / gal.

When is the problem. It is 38F. here right now and not forecast to get above 45F. today. Tomorrow is not much better. I would like to wait for temps above 50F. for a few hours before applying the acids.

I do not plan on changing my modus operandi in production work. I have never rinsed my citric acid solution on any wood, even in the long gone days of using Wolman's F&P stain. Stain longetivity and color have never been a problem.

Actually, this could work out to be an even better test. The remainer of the ipe' deck will be treated with citric and not rinsed, as is my normal procedure. I do plan on staining the test top rail before this so no further citric acid treatment will effect the test wood.

Wonder if there will be any noticable difference. In effect, three separate tests will be going on.