I was looking through a bunch of posts just now and it seems that it’s possible to downstream oxalic acid or citric acid. Can anyone confirm if this is a bad idea or not? If it is OK to do how many ounces per gallon would you mix? I figure if I do 8 ounces per gallon and I have a 10 to 1 injector I would have to put about 80 ounces in a gallon to downstream. This sounds like a big waste and I would probably just make a quart of it. Thoughts? My battery sprayer died and want to finish the job today…
Go buy a pump up to finish the job or replace your battery sprayer since you’re gonna need it sooner or later. Do you not have a 12v pump?
You can DS both, but wouldnt recommend doing it.
I do have a 12v but it’s on a proportioner and I still need to install the 3 way valve to switch between my hardlined sh/water/surfactant input and a 5 gallon bucket with drop tube. The battery just needs charging but will take a few hours.
You’re not going to be able to dissolve enough oxalic or citric in water to get a strong enough mix to downstream. Don’t you think we would all be downstreaming it if it was possible?
Five pounds of any powder is a heck of lot to try and dissolve in a gallon of water. I bet you’d be lucky to get much more than a pound dissolved in a gallon let alone 5 pounds.
Only so much of any powder can be dissolved into a gallon of water. Every substance is different. I’m sure @CaCO3Girl can fill us in on how much Oxalic can be dissolved in a gallon but I bet it’s not much more than 15-20 ounces. After that it just won’t dissolve anymore.
Unless your restoring the Golden Gate Bridge or your restoring mile long fences all day long, Get a pump up sprayer, you should have one on your rig regardless. It’s a useful thing.
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Oxalic can be dissolved into water at 90 grams per liter…or 9% at room temperature.
Having said that, I’ve only been successful at around 6% unless I add in some phosphoric acid to help it stay in solution.
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Downstream no. If a large deck or fence I dissolve it in warm water then x jet it. I usually just pump spray though. I like it strong enough it gives the instant brightening effect.
I am talking about oxalic. Never messed with citric.
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Cool thanks guys. I figured there was a reason it wasn’t done. On the test job today I had the battery die and quickly searched the forum to see if people did it. I saw a few posts where some (Clearly inexperienced) members talked about downstreaming it. We used a manual pump sprayer to finish the job. I will be installing the 3 way valve I bought tomorrow to allow me to use the 12v for more than just sh. Citric worked well. I have a question. After using the sodium percarbonate, dwelling 15 mins and rinsing with 1000 psi, I had a little furring of the wood in some places. When rinsing it looked like it was coming off but still remained here and there. I thought that using citric should calm it down and make it go away, which it did a little, but still had some areas where you could see it. Any way to remove it permanently? Should this process have worked 100%?
You’re almost always going to have some furring in spots. How much just depends on different factors like age of wood, how weathered it is, how soft it is, etc. Citric isn’t going to fix any furring. If you want to remove it permanently pull out the sandpaper. Depending how bad it is it might not even be noticeable after staining.
What do you mean worked 100%? Worked as in what?
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The medium pressure rinse and application of citric or oxalic to calm down the wood and eliminate the furring. I wasn’t sure if I moved up to 1200-1400 psi on pressure treated yellow pine and or used a little stronger citric mix would have complexly eliminated the furring. What would be the best grit to use to sand the rest off 80 maybe?
Stepping up in pressure could cause more furring. You aren’t going to remove all “furs” when cleaning or using citric acid. Furring is just part of it sometimes. I don’t get what you’re saying about the citric calming down the wood. It’s not like the acid is going to dissolve the furs or something or at least I’ve never heard of or have experienced that. Maybe someone else can chime in on that.
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80 might be too harsh depending on what surface you are sanding and the finish you desire. I don’t refinish decks anymore, but when I did, I factored in sanding (at least handrails and pickets) into the quote. We used 100 grit or 120 depending on the wood and the condition. 80 grit sometimes on the steps etc… I’ve washed a bunch of wooden fences but never refinished one so I’m not sure anyone would care about furring on a fence or not.
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I don’t think that’s the purpose of citric or oxalic. Oxalic and citric reduce the iron compounds in wood to limit tannin staining. They brighten and neutralize the wood and remove tannin stains from woods that contains tannic acid like redwood, cedar and red oak.
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This is called raising the grain in wood working. Lots of information about that all over the internet, but I like sites like this https://www.popularwoodworking.com/june-2018-239/grain-raising/
Your not working with machined lumber for interior furniture. The biggest thing to consider with sandpaper is that most people use it too long. In short, whether sanding by hand, motorized discs or pads etc, once the grit starts removing the material and the removed fibers start to build in the sandpaper or the sand paper isn’t as “bumpy” remove it, it will work more effectively. People don’t do this because we are lazy and sandpaper isn’t cheap (especially discs and pads on larger equipment). Some people suggest going around 50 for a large orbital machine, and then working up from there. 50 is somewhat aggressive. Some people suggest small random orbitals at 80, which spin at higher speeds. There are suggestions for belt sanders as well. You gotta kind of get a feel for wood. Whatever you do, dont let any equipment sit in one place too long or you will regret it. The cheapest way to do sandpaper on a motorized device is to go with something like this for small areas https://www.homedepot.com/p/DEWALT-2-3-Amp-1-4-Sheet-Sander-DWE6411/206766190?mtc=Shopping-B-F_Brand-G-Multi-NA-Multi-NA-Feed-PLA-NA-NA-Catchall_PLA&cm_mmc=Shopping-B-F_Brand-G-Multi-NA-Multi-NA-Feed-PLA-NA-NA-Catchall_PLA-71700000014585962-58700001236285396-92700010802552394&gclid=EAIaIQobChMI4Juqpv_d5wIVRcDICh0JxAXtEAQYASABEgK6kvD_BwE&gclsrc=aw.ds Because you can buy whatever sheets of sandpaper you want, rip it in quarters and use it (the base of the unit will perforate the sandpaper for vaccuuming).
When I say a large orbital, think flooring sander like this one, but the sandpaper is expensive, specially at the rental place. https://americansanders.com/2016/04/obs-18-obs-18dc/
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Good point. Another reminder is to be sure to go around and nail down or replace any nails or screws that are proud of the surface or you will be eating up sanding disks by the dozens.
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OMG, I know this and didn’t say it. What an expensive lesson that one is to learn. Thanks for pointing that out.
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I usually use 60 grit hook and loop on an orbital sander. The small difference in price makes up for it in the time saved swapping a new piece in. You can get 100 pack of 5" hook and loop for like $20 on Amazon. If you buy them local you want to get as much use out of one piece as you can. If you get them on Amazon you can go through the whole box on one job and not worry about it. I swap them out like crazy…lol
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Have you seen this? https://americansanders.com/2019/01/ez-e-extension-edger/
I really want it for going under rails on decks. I know there are extended belt sanders, but I really like this, plus this company makes tough equipment.
Pretty sure hes taking some CaCO3Girl said out of context, the citric or oxalic is to calm down the PH/Tannins/chem levels (cant remember which) not the furring.
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