# How long to cure poly before rubbing out



## torrey (Aug 7, 2011)

I have seen several threads that address the process of rubbing out poly. There is mention of making sure the finish is "cured" before doing the rub-out but no clues on how long to wait before I start.
Oh, the project is a dining table top.
I'm using "Min-wax semi-gloss fast dry formula" I'm using a wipe-on technique. I have done 5 coats of thinned (1/1 with mineral spirits) and two coats of 10% thinned product. My plan is 2 or 4 more coats at two per day to give me the base to start the rubbing out. I would appreciate any thoughts on the number of coats, (will I have enough ?). 
How long should I wait after the last coat before I start the wet sanding?


----------



## chemmy (Dec 13, 2011)

torrey said:


> I have seen several threads that address the process of rubbing out poly. There is mention of making sure the finish is "cured" before doing the rub-out but no clues on how long to wait before I start.
> Oh, the project is a dining table top.
> I'm using "Min-wax semi-gloss fast dry formula" I'm using a wipe-on technique. I have done 5 coats of thinned (1/1 with mineral spirits) and two coats of 10% thinned product. My plan is 2 or 4 more coats at two per day to give me the base to start the rubbing out. I would appreciate any thoughts on the number of coats, (will I have enough ?).
> How long should I wait after the last coat before I start the wet sanding?


Difficult question Torrey, If it were sprayed, we could consider how many mils per coat wet and deduce from there, but being hand applied unless you have a wet mil gauge [cheap get one] it's not determinable. 

Next problem is did you do wet on tacky coats or was each film allowed to dry completely before next was applied? Did you sand every coat before the next was applied? if so, then sanding will be problematic for ultra smoothness in the sense that you may go through the top layer into the one below and cause a halo area that then will need to be re-coated, do you understand? 

At this point in the finishing process, i would suggest you sand it as smooth as possible [320-400 w/d paper] apply all your coats by rattle can's in one day 4-5-6 etc. make sure you spray wet on tacky donot let it set out of tack between coats, and then wait at least 30 days for it to cure before rubbing out ok? For most finishes 30 days is considered rock hard. meaning all or 98+ percent or more of the volatiles are out of the finish by then and only resin is left ok?

With this method you will have enough build to do all your sanding steps with out cutting through to previous layers, start with no coarser than 400 w/d ok?:yes:


----------



## Dominick (May 2, 2011)

torrey said:


> I have seen several threads that address the process of rubbing out poly. There is mention of making sure the finish is "cured" before doing the rub-out but no clues on how long to wait before I start.
> Oh, the project is a dining table top.
> I'm using "Min-wax semi-gloss fast dry formula" I'm using a wipe-on technique. I have done 5 coats of thinned (1/1 with mineral spirits) and two coats of 10% thinned product. My plan is 2 or 4 more coats at two per day to give me the base to start the rubbing out. I would appreciate any thoughts on the number of coats, (will I have enough ?).
> How long should I wait after the last coat before I start the wet sanding?


Before I get into to much detail. Let me understand. Your wanting to know how long till you can rub out a poly finish? Right. You stated you'll be wiping it on right? Is it a wipe on poly? If so a wipe on poly won't give you as much protection as a oil base poly. Letting a finish cure all depends on your application, and temp. If cold temps, your finish will take longer, if warmer temps. It will cure faster.applying thinner coats will dry faster giving you 

more time to add multiple coat per day. You didn't say the look of finish you are trying to achieve. Then you said its a semi gloss poly. If you want to rub a finish using poly oil/ or water base. You should wait to rub out for as long as you can. The longer you wait to rub, the easier it is to rub a finish. 

If you try to rub out when the finish isn't cured, you take a chance on rubbing threw the finish. It's not hard to do that. 
Next thing why do you want to rub out a poly finish to begin with? If you want satin, get a satin poly, if you want semi gloss, get semi gloss, if you want high gloss get high gloss. Rubbing out a finish is rough work and not an easy subject. Before going into it I personally would read more about it. Here's a book that has helped me understand. 
It's called understanding wood finishes by bob flexner. There's others out there. Just telling you what works for me. Hope this makes sense. Good luck with your table.


----------



## torrey (Aug 7, 2011)

chemmy said:


> Difficult question Torrey, If it were sprayed, we could consider how many mils per coat wet and deduce from there, but being hand applied unless you have a wet mil gauge [cheap get one] it's not determinable.
> 
> Next problem is did you do wet on tacky coats or was each film allowed to dry completely before next was applied? Did you sand every coat before the next was applied? if so, then sanding will be problematic for ultra smoothness in the sense that you may go through the top layer into the one below and cause a halo area that then will need to be re-coated, do you understand?
> 
> ...


 I'll try to answer some questions you are raising by giving more detailed history. I started the finishing several weeks ago by putting on brush coats with the idea of creating some thicker build-up then going to wipe on for smoother finish. but there were some mess-ups and I was getting streaks and "rings" that would not cover with subsequent coats. I determined that I had been rushing it and recoating too soon. My between coat sandings began to reveal what I think you meant by halos. I finally gave up and sanded back down to wood and started over. 
This time I have gone with the wipe-on technique only. Spraying would be great but I don't have spray equipment and spray cans are not available down here. I am sanding between coats to remove dust nibs. Very light sanding with 280 grit or 000 steel wool depending on how the previous coat looks. I have considered not sanding and just doing the razor blade scrape to remove dust nibs as I have read about on other threads but was concerned about adhesion issues. I wait about 4 hours between the two coats each day and then overnight. i found that if I cut it shorter, then the new coat acts weird and doesn't flow on well, seems to feel "sticky" and not flow on well and I get more "bubbles" that don't flow out. 
I am now worried that now matter how many coats I put on, when I try to sand the final coat to polish out the small ridges that the wipe on rag leaves, it will break through the tope coat and creat the "halos" you talked about. So I'm feeling a little lost on how to proceed. 
I appologize if my ignorance on this stuff is too apparent, but I'm trying to learn.


----------



## torrey (Aug 7, 2011)

Dominick said:


> Before I get into to much detail. Let me understand. Your wanting to know how long till you can rub out a poly finish? Right. You stated you'll be wiping it on right? Is it a wipe on poly? If so a wipe on poly won't give you as much protection as a oil base poly. Letting a finish cure all depends on your application, and temp. If cold temps, your finish will take longer, if warmer temps. It will cure faster.applying thinner coats will dry faster giving you
> 
> more time to add multiple coat per day. You didn't say the look of finish you are trying to achieve. Then you said its a semi gloss poly. If you want to rub a finish using poly oil/ or water base. You should wait to rub out for as long as you can. The longer you wait to rub, the easier it is to rub a finish.
> 
> ...


The product I'm using is oil based poly. Water-based wipe-on poly is hard to come by down here in Belize, possible, but difficult. Plus I wanted the extra durability of the oil based product. My reason for planning on the rubbing out is not because of the sheen, semi-gloss will match the chairs we bought for the dining set. I am thinking of it because not matter what application technique I have tried, natural bristle brush, foam brush, wipe-on., there is still some small light "brush strokes", Even with the wipe-on rag system I still can see "stroke lines" when I look at the top in reflected light. I had thought that the only solution was to sand those out at the end. I would rather have an even/ though duller/ satin type sheen with no stroke marks than glossy finish with the marks.


----------



## cabinetman (Jul 5, 2007)

Your terminology "rubbing out" should be more specific. If you are looking for a high gloss piano type finish, or a more natural "sheen", the process is similar, but not as intensive. Any film finish...with a sufficient build, can be "rubbed out", by wet sanding to very high grits, and then a compound (like rubbing compound) can be used to bring up a luster.

Many try to rush their finish, and load up coat after coat. Truth of the matter is that each coat should be "cured" before topcoating. So, in theory, the last coat would be wet sanded and "rubbed out". Some finishers can get very good "off the gun" coatings. A wipe on finish for an oil base topcoat done in thin layers can produce a very good natural finish.

You may decide that your final look to be more natural than plasticy, and just use a very fine microfiber pad. In any case, if the finish hasn't cured completely it will feel sticky and gummy when working it. It's difficult to give waiting times as that depends on your ambient conditions, and the product you apply.










 







.


----------



## Dominick (May 2, 2011)

If your brush marks are there when it drys you'll have a hard time removing those when sanding. Try slowing down when brushing on poly. Temps are critical in getting a smooth finish. removing dust nibs you need to sand very lightly with at least 320 grit.


----------



## torrey (Aug 7, 2011)

cabinetman said:


> Your terminology "rubbing out" should be more specific. If you are looking for a high gloss piano type finish, or a more natural "sheen", the process is similar, but not as intensive. Any film finish...with a sufficient build, can be "rubbed out", by wet sanding to very high grits, and then a compound (like rubbing compound) can be used to bring up a luster.
> 
> Many try to rush their finish, and load up coat after coat. Truth of the matter is that each coat should be "cured" before topcoating. So, in theory, the last coat would be wet sanded and "rubbed out". Some finishers can get very good "off the gun" coatings. A wipe on finish for an oil base topcoat done in thin layers can produce a very good natural finish.
> 
> ...


Sorry if my terminology is mixed up.
I should have mentioned before. I am living on the coast in Belize. Temperature runs in mid 80's most of the time but humidity is high.
I am not going for the "piano fishish" look. the semi-gloss would be great but the most important thing to me is to get rid of the brush/rag stroke lines because they make it look like I don't know what I'm doing. I don't ...but I don't want everyone else to know that.:laughing:


----------



## chemmy (Dec 13, 2011)

torrey said:


> I'll try to answer some questions you are raising by giving more detailed history. I started the finishing several weeks ago by putting on brush coats with the idea of creating some thicker build-up then going to wipe on for smoother finish. but there were some mess-ups and I was getting streaks and "rings" that would not cover with subsequent coats. I determined that I had been rushing it and recoating too soon. My between coat sandings began to reveal what I think you meant by halos. I finally gave up and sanded back down to wood and started over.
> This time I have gone with the wipe-on technique only. Spraying would be great but I don't have spray equipment and spray cans are not available down here. I am sanding between coats to remove dust nibs. Very light sanding with 280 grit or 000 steel wool depending on how the previous coat looks. I have considered not sanding and just doing the razor blade scrape to remove dust nibs as I have read about on other threads but was concerned about adhesion issues. I wait about 4 hours between the two coats each day and then overnight. i found that if I cut it shorter, then the new coat acts weird and doesn't flow on well, seems to feel "sticky" and not flow on well and I get more "bubbles" that don't flow out.
> I am now worried that now matter how many coats I put on, when I try to sand the final coat to polish out the small ridges that the wipe on rag leaves, it will break through the tope coat and creat the "halos" you talked about. So I'm feeling a little lost on how to proceed.
> I appologize if my ignorance on this stuff is too apparent, but I'm trying to learn.


My apologies Torrey, i did not look to see where you were located at. 

That said, c'man is correct in the area of it's better to put on thinner coats and let them cure before moving forward as a good practice, but sometimes you have to think and work out side of the proverbial box ok? I have found with poly its better to put all the coats or most of the coats on in one round/day, if it needs more then it can be sanded after drying for a few days at least and more put on. in your case where no cans are available[ shame!] i would mask off the edge, level up my table as perfectly as possible and pour the poly on and let it flow out to the edges, not a "heavy pour", just enough to get it covered and good soft brush can help you move it around initially and when covered it will naturally flow out from there ok? Then let set for a month and sand and polish or leave alone as a satin or semi gloss finish if there is no or little dust in it. just a suggestion it works for me, maybe not others, try a sample and see ok?


----------



## Dominick (May 2, 2011)

This is hard to teach someone over typing. Especially not seeing pics of the table. And to know exactly what there trying to do. 
I think chemmy and cabby gave sound info and techniques. With the info provided


----------



## cabinetman (Jul 5, 2007)

torrey said:


> I am not going for the "piano fishish" look. the semi-gloss would be great but the most important thing to me is to get rid of the brush/rag stroke lines because they make it look like I don't know what I'm doing. I don't ...but I don't want everyone else to know that.:laughing:


If it's the brush/rag strokes...maybe it's the "rag" you are using. Just a bunched up rag, will leave mark lines. If you use a lint free "T" shirt material folded in a neat smooth pad, that will leave a neat smooth path. :yes:










 







.


----------



## Dominick (May 2, 2011)

+ 1cabby. Brushing and wiping are all techniques that aren't something you learn over night. Practice,practice, practice.


----------



## torrey (Aug 7, 2011)

cabinetman said:


> If it's the brush/rag strokes...maybe it's the "rag" you are using. Just a bunched up rag, will leave mark lines. If you use a lint free "T" shirt material folded in a neat smooth pad, that will leave a neat smooth path. :yes:
> 
> 
> 
> ...


The rag I'm using is the blue shop "paper towels"


----------



## Dominick (May 2, 2011)

torrey said:


> The rag I'm using is the blue shop "paper towels"


There's your problem. Lol


----------



## cabinetman (Jul 5, 2007)

torrey said:


> The rag I'm using is the blue shop "paper towels"


If the paper towels were better than a folded "T" shirt pad, I would have suggested them.










 







.


----------



## torrey (Aug 7, 2011)

cabinetman said:


> If the paper towels were better than a folded "T" shirt pad, I would have suggested them.
> 
> 
> 
> ...


Point taken. I had read the recomendation of using them on another website. I am willing to admit my error and will switch to the proper material for the next coats.


----------



## Dominick (May 2, 2011)

Just disregard everything I said. Lol


----------



## torrey (Aug 7, 2011)

Dominick said:


> Just disregard everything I said. Lol


NO WAY! I take everything you guy say to heart because you have been such a great help on every part of this ,my first, big furniture project.:smile:


----------



## torrey (Aug 7, 2011)

*finished project*

The t-shirt material worked much better. There is still some faint lines from the rag wiping across the piece so I will still wet-sand and polish the top after it cures for about a month. 
thanks to all who helped with advice. I'm including a couple of pictures.


----------



## chemmy (Dec 13, 2011)

torrey said:


> The t-shirt material worked much better. There is still some faint lines from the rag wiping across the piece so I will still wet-sand and polish the top after it cures for about a month.
> thanks to all who helped with advice. I'm including a couple of pictures.


looks good for your first time and the steps you used.


----------

