Need help with applying poly to hardwood floors
#1
03-03-14, 03:50 PM
Need help with applying poly to hardwood floors
I have screened/re-coated 1/2 of my 1920 craftman style bungalow. One of the bedrooms had substantial scratches, so I gave half of the room an intense sanding (to the wood). when I applied oil-based poly (as I did with the other rooms), the finish was hardly noticeable in the intense sanded areas. I generally apply 3 coats of poly.
The heavily sanded areas appeared to suck the poly into the wood, whereas the screened areas have a noticeable shine as a result. Do I need to apply some sort of base coat to the hard sanded areas? If so, should I re-sand the room to remove the initial layer of poly and start over with base coat?????
Thanks for any help! This is my first post
Chris
The heavily sanded areas appeared to suck the poly into the wood, whereas the screened areas have a noticeable shine as a result. Do I need to apply some sort of base coat to the hard sanded areas? If so, should I re-sand the room to remove the initial layer of poly and start over with base coat?????
Thanks for any help! This is my first post
Chris
#2
03-03-14, 04:22 PM
Group Moderator
Welcome!
Floors need a minimum of 3 coats of poly and more than likely 4... so if you sanded to bare wood the first coat did suck into the wood. The initial coat is usually referred to as a sealer. It raises the grain of the wood and will feel rough to the touch, so it should be lightly sanded with fine grit sandpaper before applying future coats. Lightly sand the entire floor between each coat, vacuum and use a tack cloth to clean dust before applying more poly.
Floors need a minimum of 3 coats of poly and more than likely 4... so if you sanded to bare wood the first coat did suck into the wood. The initial coat is usually referred to as a sealer. It raises the grain of the wood and will feel rough to the touch, so it should be lightly sanded with fine grit sandpaper before applying future coats. Lightly sand the entire floor between each coat, vacuum and use a tack cloth to clean dust before applying more poly.
#3
03-03-14, 04:27 PM
Thanks XSleeper!!! Just to confirm, there is no need to apply a "base" coat (other than standard poly)??? I wasn't aware of there being a specific coat for the "base" but wanted to confirm. cheers!!
#4
03-04-14, 03:47 AM
With varnish you use a 'sanding sealer' for the first coat but it's not always compatible with poly. With poly you might thin the first coat a little but you normally use the same poly for all coats. There are some that claim if you want a satin finish you need to start with gloss and then switch to satin but I never have.
Do you sand [and remove the dust] between each coat of poly? It's normal for the first coat to be blotchy but it should get better each time you sand and recoat.
Do you sand [and remove the dust] between each coat of poly? It's normal for the first coat to be blotchy but it should get better each time you sand and recoat.
#5
03-04-14, 04:39 AM
I haven't sanded between coats. Up until now, the finish looks great! I may lightly sand this first coat, then continue with the remaining coats. Thanks for your input! Your advice is very helpful!
#8
03-04-14, 02:50 PM
Group Moderator
Just to clarify - Mark is talking about a light, scuff sanding between coats, as this creates nooks and crannies for the next coat of poly to flow into when it's wet in order to create a mechanical bond between the coats. Without this step, it's possible for the coats to separate from each other and peel.
#9
03-04-14, 02:57 PM
Group Moderator
220 Grit would be an example of the "fine grit" sandpaper you would use between coats. If using a 3M Sandblaster pad their "fine" is 180 for between coats.
#10
03-04-14, 03:26 PM
10-4... Thanks guys! This is a tremendous help and great advice!
Will the fact that I screened half of the room and sanded the other half have an adverse effect to the finish appearance?
Will the fact that I screened half of the room and sanded the other half have an adverse effect to the finish appearance?
#12
03-04-14, 05:52 PM
Here's a picture from screen sanding three times with 80 grit, 120 grit, 120grit paper. Applied one coat of poly and sanded (220 grit)/vacuumed. These are some of the spots that show the contrast between hard sanded and lightly sanded areas. Does it look like I did anything wrong?
#13
03-05-14, 04:07 AM
A little hard to tell from just a close up shot but it looks like it should be ok. Wood naturally has hard/soft areas in it. The soft areas will absorb more finish than the hard areas which results in more roughness and less gloss. Each coat helps to minimize this effect. It generally takes 3 coats [sanding lightly between coats] to get an even, smooth finish.
#14
03-05-14, 05:21 AM
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Looking at the picture, my take is that the hard sanding opened more pores in the wood, and consequently led to more darkening that did the lightly sanded areas. And, I would not expect further coats of poly to change the contrast you have now. I think you have two undesirable alternatives: either live with the contrast (at least a month to see if you still care), or re-sand the entire floor starting with 80 grit all over, then 120 all over.
#15
03-05-14, 12:18 PM
Bigfred - the hard sanded areas are lighter in color and the soft sanded (screened) area is a darker brown. My hope is that once I apply poly, it will absorb more into the harder sanded area and blend colors more evenly.....?
