water base poly???

larry merlau

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Delton, Michigan
got a table that had deft lacqr on it first i think,, then had poly afterwards.. anyway i gave it a sanding again and then gave it a coat of shellac seal coat..zinzer,, well after it had set a bit it got alittel cracking in one area i want to apply water base poly on it for the final caot what do you gurus suggest i do now???? touch sand the shellac and go with the poly??? tonight its gonna happen so speak up please:)
 
ok letsd regrtoup

what the hay should i use for kitchen table top thats gonna get used for more than just eatin.. i have given it a coat of shellac cuz i am not sure what was under it.. and the wize ones say that shellac is the go between in all things finish:) got another day cuz the boss said i could so i hope to get a answer that will work,, and water base isnt in the equation any longer just a hard durable eatin finish.. and i am gettin hungry. no main meals till its back in service
 
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did you sand and wash with either spirits or tsp before shellac? if so then the shellac is bonded.......i`d use either a poly for floors......or (my choice) a conversion varnish, m.l.campbell makes a good-n...
 
did you sand and wash with either spirits or tsp before shellac? if so then the shellac is bonded.......i`d use either a poly for floors......or (my choice) a conversion varnish, m.l.campbell makes a good-n...

ok tod help this dumb nut out alittle what is tsp??? i sanded then wiped it down alot with dna.. before sprayin. ya got alink wher ei could find sum ml varnish tod
 
tri-sodium phosphate...
m.l.campbell is usually carried by folks who carry pittsburg?

nope didnt use any of that me and chemistry wasnt freinds:) but washing it down with alchol ,,would that do it too? the second coat seemed to go on ok after i touched sande the first coat.. i saw what caude my crakles it was the sun coming threw the screen:huh: yup had me eyes ckd yesterday:0 ok tod i will chk for a pitts burg place is there anothe rname for it ,,like magnalc conversion varnish? is that what jason used on his last project.. it was pre cat lac of some sort,, how is the clean up does it dry hard and clog things up fast?
 
Larry,

I PM'd you on this but thought I'd toss it into this thread for comments from others. I've used water-borne finishes on only one project so far, but have another ready for topcoat now. I used Target filler, sealer and conversion varnish on the kitchen island top I posted recently. My experience is based on a lot of research on this and other forums plus some actual usage now. I plan to use these products as well as Target USL going forward.

One thing I learned from researching the Target products is to wipe down the piece with a 50/50 mix of DNA and water between each coat. This removes fine dust and any oily fingerprints, etc.
 
got a table that had deft lacqr on it first i think,, then had poly afterwards.. anyway i gave it a sanding again and then gave it a coat of shellac seal coat..zinzer,, well after it had set a bit it got alittel cracking in one area i want to apply water base poly on it for the final caot what do you gurus suggest i do now???? touch sand the shellac and go with the poly??? tonight its gonna happen so speak up please:)


Give me a break. :eek: Chemestry has to come to play sooner or later. Four layers of incompatible chemicals. Poly over Lacquer deft is OK but Shellac over Poly? and then Waterbased? Lacquer is a solvent based product that after the solvent evaporates the finish is hard and done. Poly is a slow drying finish that exudes vapors for years, then add an alcohol solvent finish Shellac over the top which seals the fumes from the Poly and creates the crackle effect, and to top it off with a water based product and we all know what water does to shellac finish. You should be creating some interesting Antique Faux Finish. Sounds like HGTV Decorating on a doily

Sorry to be so blunt but there is a great deal of Science and Chemestry that goes into proper finishing.
 
Sorry to be so blunt but there is a great deal of Science and Chemestry that goes into proper finishing.[/QUOTE]

well Mr Simpson, this is why i asked for some assitance and got what help i got here and other places,, see i never said i was chemist, and asked what to do.. from what little i know shellac is the go between coat to lay another film finish down over a non compatible one...According to many finishers that are much more expeiernced than me,,,,, i had sanded this table top down to almost bare wood,,veneer,, and then gave it two coats of shellac to make the change. i wasnt sure of the previous coatings.. and this is just a eatin table..i hadnt gotten a definative answer and hadnt heard your directions prior. so i done what thought to be correct and asked a paint distributor there opinion as well to compare againt what i had heard here and from others in the know more than me.... they said to use the shellac as i have done and then to use a precat lacquer.. over that.. so i went with there choice.. see they sell paint and therfore should have some idea of there products use,, much more than i who was looking for a solution.. sorry if my ignorance and lack of reasearch offended anyone.. next time i will do more leg work. but i can say that this finish i have on eher now is real tough compared to the last one.
 
I used Minwax Polycrylic on some bathroom cabinet projects at Steve Clardy's recommendation and was pleased with the results. But I think that the pre-cat lacquer was a better choice for a dining table. We have an amish-made dining room set which has a pre-cat finish. We've had it almost 8 years now and while there are a few minor scratches from things getting dropped or dragged across it it still looks very good.

My question is how did you like spraying that stuff? I've always read that it is some nasty stuff.
 
Sorry to be so blunt but there is a great deal of Science and Chemestry that goes into proper finishing.

well Mr Simpson, this is why i asked for some assitance and got what help i got here and other places,, see i never said i was chemist, and asked what to do.. from what little i know shellac is the go between coat to lay another film finish down over a non compatible one...According to many finishers that are much more expeiernced than me,,,,, i had sanded this table top down to almost bare wood,,veneer,, and then gave it two coats of shellac to make the change. i wasnt sure of the previous coatings.. and this is just a eatin table..i hadnt gotten a definative answer and hadnt heard your directions prior. so i done what thought to be correct and asked a paint distributor there opinion as well to compare againt what i had heard here and from others in the know more than me.... they said to use the shellac as i have done and then to use a precat lacquer.. over that.. so i went with there choice.. see they sell paint and therfore should have some idea of there products use,, much more than i who was looking for a solution.. sorry if my ignorance and lack of reasearch offended anyone.. next time i will do more leg work. but i can say that this finish i have on eher now is real tough compared to the last one.[/QUOTE]

larry,
forums such as fww exist for the purpose of sharing knowledge so the legwork you speak of was done in part here........letting everyone know the results will help others down the road who may be faced with the same issues.
thanks for sharing!
 
well as i have posted prior, first thing i got some craklin, light but there,, i would quess it was a reaction between the shellac and what was below it.. i had sanded it with a RO with 220 grit to get the scale and to get some bite.. i then took and washed it down with DNA straight stuff wanted to try and get the old oil or grease if there was any left off.. then applied 2 coats of dewaxed shellac... then asked for assistance i thought i wanted water based or waterborne poly on top, but from the sources i heard from at the time i decided against that.. I AM NOT SAYIN that those who said water style finish were wrong i just made my own mind up on what to use.. RIGHT or WRONG. based on what i heard from my sources. then a i touch sanded the shellac with 220 again and gave it 2 heavy coats with a improperly adjusted gun,, tryun to run straight stuff not thinned. me and the thick stuff arent in tune yet. then waited for 24 hrs, touch sanded the precat lacqur solvent based, and then gave it another medium coat, got the gun workin better with the thick stuff but still not happy with it. after that dried i took and thinned it even though the paint guys said i didnt have to. i was told to go ahead and thin it, if it wasnt flowing right from my gun and its settings. so the last coat went on better, and its a tough finish, the sand paper would rather slide over it than get ahold.. Matt,, as for right now the stuff is ok, will know more later. i am going to try it on a fresh piece of wood to see its results. but you want to clean your gun after each round, not coat, but afternoon or night or whenever your working with it DONT let it sit in your gun over night.. it dries fast and hard. all this is from a first time user without a tod lookin over my shoulder which i wish had been there!!! i believe the needle assembly i am using is a 1.5 matt and i had to open the fluid adjustment to get it to work better but its not right yet. dun ramblin and i can have some supper now:D
 
Larry, I am sorry if I came on strong but I see over and over again where fellows are encouraging folks to layer incompatible finishes. Such as Lacquer over Oil or Shellac over BLO etc.

Water born finishes are suppose to be "Breathable" where they will allow Molecule movement to pass through, the same as Latex Paint. IMHO they are not appropriate for top coats and finish coats where exposure is common. (I know this raises a reaction with a few and contrary to some thoughts) But the manufacturer says it Breathes and if it breathes then how can it seal?

I use WB Poly when I have a particular piece of wood where I do not want a color change that you get from ambering finishes such as Poly and Lacquer or Deft, or BLO, etc. I follow that with a hard finish like Poly to seal and protect the piece.

I appreciate your asking for advise but you did so after several different finish changes and ask the advise before the final coat. Already you had violated the rules of engagement and I am sorry to say that it may occur that the Crackling effect you experience is not done, sometimes these take a long time to manifest themselves as the solvents exude through the finish and is captured by the sealing finishes creating blisters and lifting.

The finish is only as good as the bond to the surface below. Dissimilar finishes will not bond. And therefore the blistering and Crackle occurs.

I do hope you keep us informed on your progress and also want you to take my statements as informative and not critical. You are not the only one to make these mistakes.
 
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Bill,

This is an area where many of us are weak, and especially me. I think it's because there's such a confusing array of products and claims, and it's hard to keep it all straight because people cloud the issue with details about each finish.

"You can use Y, except for Yz, and if you do Yz use X first, or you could use 22a, but 22b is not a good idea because of incompatible reactions..." ;)

People get confused and testy, it's understandable. It's like explaining Deconstruction to undergraduates, I've seen smart people get lost in their own details, and lose the whole class, when the truth is Deconstruction's pretty simple stuff. If you stick to the basics, all the details follow.

So, can you take us (me) to school on this one? I've got lacquer (water and oil), poly (water and oil), shellac, and a whole bunch of other things (mostly oils and thinning driers like naptha) in my shop. What should I be using, what combinations are good, and what should I avoid?

Seems like every durned time I do a project, I'm doing an experimental finish. And every time I settle on something, in the back of my mind I'm hearing Smith and Jones saying 'I hate that look', and if I switch to what they advocate, Brown says 'I can't believe you didn't do X" ;)

HELP! :dunno:

Thanks,

Bill
 
Some say to first wipe with BLO to "pop the grain" (BS) and others say to shellac to get the results you want.

Secret is to seal the wood with an ambering product such as Deft, Lacquer, Shellac. to make a sanding sealer so that you can best prepare the serface for finishing (much like you use a Primer for paint) Those products are solvent based and dry instantly and leave a hard surface for doing what you want as a finish coat.

Oil based products take tme to cure. BLO, Poly, and varnish take a while to cure or dry. If you use them then continue with an oil based product such as Poly or Varnish. If you choose Lacquer or Shellac as the base coat then you can use any finish material you wish as they are solvent based and will dry completely when the solvent evaporates. Soft sanding will make a good base for any finish you desire.

Problem comes whenyou use an oil based material as a seallant or to"Pop" the grain :( I hate that term.... BLO is an oil and it takes several days to cure or dry. After a couple of day you can apply a solvent based finish but you will not get a bond but rather a coating. It looks like a surface finish but it is not bonded to the surface below, as the oil base material is still exuding fumes and creating a barrier to the bond.

Some are successful (they think) because all looks well and the finish dries OK but actuallyu the bond they want is not ther and a peeling or lifting of the finishe is bound to happen.

Secret is to use a solvent based material as the "sealer" and then you can choose the finish coat to you liking. Bit if you use an Oil base substance first, then you have to follow up with an oil base finish.
 
Some say to first wipe with BLO to "pop the grain" (BS) and others say to shellac to get the results you want.

Problem comes whenyou use an oil based material as a seallant or to"Pop" the grain :( I hate that term.... BLO is an oil and it takes several days to cure or dry. After a couple of day you can apply a solvent based finish but you will not get a bond but rather a coating. It looks like a surface finish but it is not bonded to the surface below, as the oil base material is still exuding fumes and creating a barrier to the bond.

Secret is to use a solvent based material as the "sealer" and then you can choose the finish coat to you liking. Bit if you use an Oil base substance first, then you have to follow up with an oil base finish.

thank you for your comments, i even agree with some of them:D, in my case i think i done all i could, to eleimante my troubles, from the info i had, when i spoke of crakilin it wasnt as i may have implied, i belive it was more poor spray pattern in combination with the chemical reaction. i couldnt sand this down any more than i did, because of the veneer. this had been sanded and reastained before and by me without any knowlege at all about venner and this coat over that coat. the only reason i was thinking of water born finsih was becasue of that is where we are all headed someday, and thought this would be asafe place to try it,,all i do is eat on this dont show it nowhere.. a scrap piece of wood would work for trial and error but this wouldnt have the past history on it..and by itslef would be a fairer comparison.. for a new finish test.. and i am smart enought to know that if it wasnt what i was lookin for i would take into consideration that it did have previous finish on it.. i do try to look at all the angles bill. and ask questions.
 
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Secret is to seal the wood with an ambering product such as Deft, Lacquer, Shellac. to make a sanding sealer so that you can best prepare the serface for finishing (much like you use a Primer for paint) Those products are solvent based and dry instantly and leave a hard surface for doing what you want as a finish coat.

Bill, just last week I read an article in Popular Woodworking (October 2008 #171) by Bob Flexner titled "Shellac and Sealing Wood" that changed my understanding and use of sanding sealers and shellac. In it he questions the use of special "sanding sealers" to prepare surfaces. He believes that they weaken the bond between the finish and the wood. He states that sanding sealers came about because some finishes (alkyd varnish and nitrocellulose lacquer) are difficult to sand and since that first coat (the sealing coat) tends to raise and lock the fibers in place (bare wood only) it requires sanding to level and smooth. He recommends that instead of using a separate product, you should thin the varnish or lacquer for that first coat making it dry harder and faster and easier to sand. He also claims that using shellac as a sealer to improve adhesion for the next coat is not beneficial. He believes that there is always risk in applying one type of finish over another. He does believe that shellac is probably the best product to use a barrier coat to block of some problem in the wood such as resin in new wood or residual wax from strippers, silicone oil from furniture polish and odors from smoke/urine in previously finished surfaces. I would suggest everyone to read the article themselves and not rely on my own interpretations. I hope I have not "twisted" the information that Bob Flexner was conveying in the article. I have been known to "get it wrong" (just ask my wife).:)

I am not saying that your statement about a "sanding sealer" is like a primer is wrong, but that it may only apply depending on the situation. Larry's problem is a difficult one in that he is not starting from a new wood, but a one that had been finished twice (I hope I got that right) before he started refinishing it. I am most interested in how this discussion progresses forward to what finishes are compatable with others and especially how to go forward when you have a problem like Larry's. Your statements about being cautious of using long curing products under short curing products make sense.
 
i`ve been using sanding sealer under nitrocellouse for well over 20yrs with zero failures.........lotsa gallons there:eek:........
 
From one Bill to another Bill.... I also read that article and I agree with a lot he says But it is HIS Opinion. As a sanding sealer I have always used a "Watered down " version of the final finish coat/ IE. I cut Lacquer really hard 200% or better and Shellac the same ratio as well as thin out Poly to make a sanding sealer. (I'm too cheap to buy "Special Sanding sealers") Hy-Klas makes a sanding sealer that is really a gem to use but almost impossible to find. They will sell it direce from thye Plantin Louisvill, KY but the shipping kills you. Next tim I'm in Louisville I plan to drive by and buy a gallon. Divide into quart jars and use it. But until then I will still thin my finish coat to make a sanding sealer.

As for shellac as a sanding sealer, It has been the "Industry Standard" for longer than he has been doing WWing so he debunking an old tried tradition... Non the less, just because we have always done it that way doesn't mean it is the best way. I learn new stuff every day and I may stand corrected, but I have never had any failures unless I try to mix finish types in the wrong order. Solvents on the bottom and oils on the top... Remember that and you won't get the crackling and orange peel finish. Fisheye comes from Silicone contamination. whole 'nuther subject.
 
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