# Poly... Before or after assembly?



## rtilghman (Jan 23, 2015)

As I detailed in another post, I'm building a bunch of drawers as part of a set of built-ins for my kids. With all the wood sanded with 320 I'm ready for assembly, but it occurred to me that maybe I should poly first?

I've found a lot of conflicting opinions online, figured I'd see what the folks here thought. As near as I can figure:

- poly first will make it easier to ensure an even coat on all the pieces (50 total). It'll definitely make it easier to do the post first coat 320 sand job. Downside is finding space to dry all the parts and do the work.

- assembly first will make drying easier since the parts will hold themselves up, and I won't tag the joints or have to deal with glue on top of poly. Downside is the sanding, which will kind of suck in the corners.

Thoughts? What do people generally prefer for drawer boxes? My drawers are 15.75 x 27.5 x 3.5/6.5/9.5.

Thanks,
Rick


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## Steve Neul (Sep 2, 2011)

In order to finish the wood before assembly you would have to mask off everywhere you would be putting glue. That's not worth the trouble for me. I always build the drawers and then finish.


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## Nick Sandmann (Oct 24, 2014)

I'm not sure why you're worried about glue on top of poly. Are you using CA or some kind of polyurethane glue?

If you're using other wood glues(yellow, hide, etc...) you can literally just peel the the glue off the finish. Standard wood glues won't bond to finish(CA and poly glues being an exception), so squeeze out can just be scraped off with your finger nail, this is one of the advantages of finishing before assembly.

Sanding shouldn't be a concern. Regardless whether you finish before or after assembly, I would do the final sanding before the glue up. The only reason I'd sand after gluing up a project would be if I didn't pre-finish it and needed to deal with squeeze out.

It depends on the project, but I've been leaning towards finishing before assembly for most of what I build these days(there are always exceptions though).


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## Toolman50 (Mar 22, 2015)

Assemble the drawers and then apply your finish. 
You may have some final sanding, filling, scraping to do after your glue-up.


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## UnisawGuy (Jul 20, 2014)

I finish all interior surfaces before I cut the joinery.


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## rtilghman (Jan 23, 2015)

Thanks for the replies everybody, definitely seems like a polarizing question! 

To a few of the questions/comments, I'm considering assembling first to avoid getting stain on the joints. I'm using rabbets with dados, and there's a bunch of surface.

I'm going to be applying with a foam brush with titebond II, so I'm a little less concerned about overage. However, as with anything else mistakes happen, and the fact that glue doesn't adhere very well/at all to poly (minwax satin) means my joints will suffer if I screw up here and there.

Tough call... I really like the idea of doing at least the first stain pre-assembly, but the counter arguments are strong. Seems like a toss up, maybe I'll flip a coin. 

Rick


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## Steve Neul (Sep 2, 2011)

I would use a glue bottle to apply the glue but there is no reason you couldn't use a foam brush. Any glue you get on the surrounding wood just wash it off with a wet rag. As long as you clean the glue off soon after you get in on the wood there will be no glue stain from it.


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## rtilghman (Jan 23, 2015)

Steve Neul said:


> I would use a glue bottle to apply the glue but there is no reason you couldn't use a foam brush. Any glue you get on the surrounding wood just wash it off with a wet rag. As long as you clean the glue off soon after you get in on the wood there will be no glue stain from it.


Sorry, I typed my reply on my phone, reread it and it definitely was a little confusing.

I'm going to be using foam brushes for the Poly, not the glue. The glue I'll just apply using the bottle, clamp it, nail it (18g brads), and then wipe off the overage with a wet paper towel.

The issue is if I get poly on either the rabbets or in the dados as I'm working. I should be able to control it pretty well, you just never know and I'm an overthinker. 

Best,
Rick


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## mikeswoods (May 18, 2009)

UnisawGuy said:


> I finish all interior surfaces before I cut the joinery.


This method is a good one---as it leaves the glued joints without any finish----Thanks,unisawGuy--


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## Wendel17 (Apr 20, 2009)

rtilghman said:


> Sorry, I typed my reply on my phone, reread it and it definitely was a little confusing.
> 
> I'm going to be using foam brushes for the Poly, not the glue. The glue I'll just apply using the bottle, clamp it, nail it (18g brads), and then wipe off the overage with a wet paper towel.
> 
> ...


As long as you mask the rabbet or dado before you finish with the stain and / or poly, you should still have enough raw wood left for glue to hold. If you use a good quality tape, it'll eliminate most of the bleed-through.


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## rtilghman (Jan 23, 2015)

So, I ended up assembling first. While I liked the idea of polying first, 50 some odd pieces of drawer parts seemed like too much to try and manage in my fairly small garage floor/box/clutter workspace. It'll be tough enough just figuring out how to do it with 10 sizable drawers.

I really like the idea of polying before I even cut the dados/rabbets, but - pardon my language - that seems to take a big set of balls...  I can't imagine how frustrating it would be if I screwed up a cut on a board I'd sanded to 320, polyed, resanded with 320, and then polyed again. Ugh.

I will say that I learned my lesson on sanding rabbets/dados for drawers. Even having a lot of painting/sanding experiences, I underestimated how much wood I might lose sanding with 220, and failed to consider the fact that the outside edge of the back/front dados should not be sanded at all... since they mate to the side and will be invisible. Didn't lose a lot, but I definitely ate 1/16 or so off some of the corners. A mistake only I will notice, but man, talk about frustrating...

Thanks again for all the help everybody, really appreciate it. Drawers look great, super excited to begin the poly/sand/poly process and mount these suckers!

Best,
Rick


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