Working on a paint job on my Formica counter top (primer, granite spray
paint, and polyurethane finish). This is the first time I've used
Polyurethane and I'm getting different directions from different sources.
My question for anyone who would know:
Do I need to sand between coats of Poly?
I'm going for 4-6 coats, have the first coat on and dry, and am not sure if
I should sand or not. The directions on the can say "recoat in 6 hours. If
first coat is allowed to dry 48 hours, sanding is necessary between coats."
Does this mean if I don't wait 48 hours that I do not need to sand?
Thanks in advance for any help.
Icon
Exactly what I did Mike, and it worked great!
The 220 sandpaper didn't work that great but the steel wool did. Plus it
made it easier to see where I've put the second coat. Helps to keep an even
coverage.
It's looking great! A few more coats to go (takes a day to recoat, and
being busy at work isn't helping).
Icon
"Mike Marlow" <[email protected]> wrote in message
news:[email protected]...
>
> "Hardcore Icon" <[email protected]> wrote in message
> news:[email protected]...
>> Thanks John!
>>
>> Maybe I'll hit it just a little bit with some 220, it hasn't been 48
>> hours
>> but if it will make a better finish then that's what I'll do. But the
>> directions only said to sand if it's passed 48 hours so going by that I
>> guess I don't *have* to sand.
>>
>
> Try it by the manufacturer's recommendation, but don't be surprised if the
> second coat drags if you don't scruff between coats. Poly does not bite
> into the previous coat, it only lays on top, so the smoother the
> underlying
> surface, the better. I would not use 220 though. I'd just knock it down
> with steel wool or 3M pads. All you need to do is break the glaze for a
> little tooth.
>
> --
>
> -Mike-
> [email protected]
>
>
Is there not the concern that the finish has to completely harden before
sanding? I would think (w/ nothing to back it up) the longer the better.
For the sake of the after-sand finish quantity/quality. Like multiply x 5
to be safe. Fives a good average number for things like that in general,
any opinions? Quit asking questions, you're confusing us.
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I have read in here that (i)only sand is to worsen the finish, OR (ii)work
in a polish regime,which may include some form of sanding to improve the
finish. If you can recoat before the dry time w/o sanding, and you're not
gonna super-finish, thats what I'd do.
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Hardcore Icon wrote:
> Working on a paint job on my Formica counter top (primer, granite spray
> paint, and polyurethane finish). This is the first time I've used
> Polyurethane and I'm getting different directions from different sources.
>
> My question for anyone who would know:
>
> Do I need to sand between coats of Poly?
>
> I'm going for 4-6 coats, have the first coat on and dry, and am not sure if
> I should sand or not. The directions on the can say "recoat in 6 hours. If
> first coat is allowed to dry 48 hours, sanding is necessary between coats."
>
> Does this mean if I don't wait 48 hours that I do not need to sand?
>
> Thanks in advance for any help.
>
> Icon
maybe it's laziness on my part, but I pretty much always sand between
coats. it's often easier than inspecting all surfaces visually- a fast
swipe of each surface with medium-to-fine-ish sandpaper will tell me by
feel how the last coat flowed out, whether there is any crud stuck in
it, etc.
Remember that you may need to sand after the first coat if any grain is
there to raise.
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yes, for a mechanical bond also after mfr rec'd time passed. My experience
is if the wood is "rough" to begin with it may help between coats
(specifically after spit coat), but that wood may not be worth improving.
If its nice in the first place, sanding after the second coat and after
gives little if any improvement for the amount of effort req'd.
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Hardcore Icon wrote:
> Working on a paint job on my Formica counter top (primer, granite spray
> paint, and polyurethane finish). This is the first time I've used
> Polyurethane and I'm getting different directions from different sources.
>
> My question for anyone who would know:
>
> Do I need to sand between coats of Poly?
Yes.
320 wet-dry on block, wet, with mineral spirits. Takes about
2 minutes to wet sand a 1 x 3 foot bookshelf between coats.
Wet paper cuts _fast_, like an eraser. Hardest part is not
sanding through.
> I'm going for 4-6 coats, have the first coat on and dry, and am not sure if
> I should sand or not. The directions on the can say "recoat in 6 hours. If
> first coat is allowed to dry 48 hours, sanding is necessary between coats."
>
> Does this mean if I don't wait 48 hours that I do not need to sand?
>
> Thanks in advance for any help.
That many coats, you should thin the poly 50% and wipe it on.
Rub out with gray Scotchbrite between coats.
Ron Magen wrote:
> What 'Pop' says . . . with a couple of provisos . . .
>
> I came into this late, so don't really know if we're talking about 'solvent'
> or 'water-based' Poly. I'll presume solvent, because of the suggestion to
> use 'Mineral Spirits'.
>
> When I Varnish trim, 6 coats is usually the minimum. The first coat thinned
> 50 percent. 'Cure' for 24-hours. {At this point, the surface guides my
> sanding - which is more dependent on the 'prep work'}. Lightly 'scuff sand'
> with 220. Wipe with solvent dampened cloth.
>
> Second coat thinned 25 percent. 220 again.
>
> Third coat 'full strength'. Scuff sand with 320. Follow the same process and
> use finer & finer paper - 400, 600. Let cure 'hard' - at least 72-hours.
> Lastly, a fine automotive 'compound' and a couple of well-buffed coats of
> wax.
>
> The 'modern' or 'synthetic' varnish {Poly} is handled the same.
>
> For 'in-home' use my preference is for the Water-Based Poly. I find the
> surface to be harder & more abrasion resistant. In addition, there is no
> 'burned hydrocarbon' smell when I use it {we have gas heat, etc.}. I use the
> same application 'technique', only do not 'thin', or as much, depending on
> the 'age' of the can. The H2O stuff flows much more easily. Also, 'dampened
> with water', vs. 'solvent'.
>
> I don't use the 'wet sand' method, so really have no comment on that.
Flooding the paper with mineral spirits keeps it from clogging,
making it cut what feels like 10x faster. Those little "pills"
that form on the paper hold the paper away from the varnish,
preventing it from cutting. The wet paper seems to last forever,
too. You can scuff sand an entire bookcase with a single quarter
sheet of 320, and the paper still feels new. You could use stearated
paper for nearly the same effect except on waterborne.
I prefer mineral spirits because it won't swell the wood
if it gets through any breaks in the new finish. Won't
hurt the finish provided it's dried hard overnight.
Wet sanding with 1500 or 2000 grit from your Scary-Sharp
supplies puts on a nice shine after cure.
"Hardcore Icon" <[email protected]> wrote in message
news:[email protected]...
> Thanks John!
>
> Maybe I'll hit it just a little bit with some 220, it hasn't been 48 hours
> but if it will make a better finish then that's what I'll do. But the
> directions only said to sand if it's passed 48 hours so going by that I
> guess I don't *have* to sand.
>
Try it by the manufacturer's recommendation, but don't be surprised if the
second coat drags if you don't scruff between coats. Poly does not bite
into the previous coat, it only lays on top, so the smoother the underlying
surface, the better. I would not use 220 though. I'd just knock it down
with steel wool or 3M pads. All you need to do is break the glaze for a
little tooth.
--
-Mike-
[email protected]
"Hardcore Icon" <[email protected]> wrote in message
news:%[email protected]...
> Exactly what I did Mike, and it worked great!
>
> The 220 sandpaper didn't work that great but the steel wool did. Plus it
> made it easier to see where I've put the second coat. Helps to keep an
> even coverage.
Watch out for steel wool filings and water-based finishes. It's a bitch
getting rid of the rust spots.
Gotcha!
Since this is not wood (it's a countertop that is painted to look like
granite), whatever dust particles can't really be seen anyway. Good reason
not to sand.
The main goal here is to get a real good thick protective coat. Just put
the second coat on a few hours ago.
Looks good.
Thanks.
Icon
"Pop`" <[email protected]> wrote in message
news:xqgph.3549$AM4.3343@trnddc07...
> Hardcore Icon wrote:
>> Working on a paint job on my Formica counter top (primer, granite
>> spray paint, and polyurethane finish). This is the first time I've
>> used Polyurethane and I'm getting different directions from different
>> sources.
>> My question for anyone who would know:
>>
>> Do I need to sand between coats of Poly?
>>
>> I'm going for 4-6 coats, have the first coat on and dry, and am not
>> sure if I should sand or not. The directions on the can say "recoat
>> in 6 hours. If first coat is allowed to dry 48 hours, sanding is
>> necessary between coats."
>> Does this mean if I don't wait 48 hours that I do not need to sand?
>>
>> Thanks in advance for any help.
>>
>> Icon
>
> Duhhhh, do you suppose that's what it says?
>
> Reason to sand: Air is not dust free; can see dust particles.
> Reason not to sand: In specs per the directions and surface looks
> perfectly fine, no dust, bubbles or other contminants visible.
>
The poly is still setting up in the 48 hour time period, so the next coat
will adhere to the previous one quite well. After 48 hours you need to
scuff the surface to get decent adhesion between coats. The manufacturer's
recommendation has nothing to do with controlling the smoothness of the
coating.
And....you will have a LOT better results if you thin the poly in the can
down with mineral spirits. I use 2 parts poly and 1 of thinner. Fewer
brush marks and runs and bubbles. That message is not on the can.
Downside, because you are applying a thinner finish, you will have to add
another coat to get a good build up. But its worth it.
Old Guy
"Hardcore Icon" <[email protected]> wrote in message
news:[email protected]...
> Working on a paint job on my Formica counter top (primer, granite spray
> paint, and polyurethane finish). This is the first time I've used
> Polyurethane and I'm getting different directions from different sources.
>
> My question for anyone who would know:
>
> Do I need to sand between coats of Poly?
>
> I'm going for 4-6 coats, have the first coat on and dry, and am not sure
> if I should sand or not. The directions on the can say "recoat in 6
> hours. If first coat is allowed to dry 48 hours, sanding is necessary
> between coats."
>
> Does this mean if I don't wait 48 hours that I do not need to sand?
>
> Thanks in advance for any help.
>
> Icon
>
>
>
>
"Hardcore Icon" <[email protected]> wrote in message
news:[email protected]...
> Working on a paint job on my Formica counter top (primer, granite spray
> paint, and polyurethane finish). This is the first time I've used
> Polyurethane and I'm getting different directions from different sources.
>
> My question for anyone who would know:
>
> Do I need to sand between coats of Poly?
>
> I'm going for 4-6 coats, have the first coat on and dry, and am not sure
> if I should sand or not. The directions on the can say "recoat in 6
> hours. If first coat is allowed to dry 48 hours, sanding is necessary
> between coats."
>
> Does this mean if I don't wait 48 hours that I do not need to sand?
>
> Thanks in advance for any help.
>
> Icon
>
That is correct; if you recoat quickly the new coat can bond. If you wait
you have to rough the surface up a bit.
I like to put on a few coats, sand (well, steel wool) and then put on my
final coat.
The more often you sand, the better chance you have of getting a smooth
final surface. But it is work and makes for a thinner coating.
Hardcore Icon wrote:
<snip>
> The directions on the can say "recoat in 6 hours.
> If
> first coat is allowed to dry 48 hours, sanding is necessary between
> coats."
>
> Does this mean if I don't wait 48 hours that I do not need to sand?
<snip>
Yep.
After 48 hours, you no longer get a chemical bond so you have to sand
to get a mechanical bond between coats.
Pretty much standard for LP.
Why not talk to the factory for latest update.
Lew
What 'Pop' says . . . with a couple of provisos . . .
I came into this late, so don't really know if we're talking about 'solvent'
or 'water-based' Poly. I'll presume solvent, because of the suggestion to
use 'Mineral Spirits'.
When I Varnish trim, 6 coats is usually the minimum. The first coat thinned
50 percent. 'Cure' for 24-hours. {At this point, the surface guides my
sanding - which is more dependent on the 'prep work'}. Lightly 'scuff sand'
with 220. Wipe with solvent dampened cloth.
Second coat thinned 25 percent. 220 again.
Third coat 'full strength'. Scuff sand with 320. Follow the same process and
use finer & finer paper - 400, 600. Let cure 'hard' - at least 72-hours.
Lastly, a fine automotive 'compound' and a couple of well-buffed coats of
wax.
The 'modern' or 'synthetic' varnish {Poly} is handled the same.
For 'in-home' use my preference is for the Water-Based Poly. I find the
surface to be harder & more abrasion resistant. In addition, there is no
'burned hydrocarbon' smell when I use it {we have gas heat, etc.}. I use the
same application 'technique', only do not 'thin', or as much, depending on
the 'age' of the can. The H2O stuff flows much more easily. Also, 'dampened
with water', vs. 'solvent'.
I don't use the 'wet sand' method, so really have no comment on that.
Regards & Good Luck,
Ron Magen
Backyard Boatshop
"Father Haskell" <[email protected]> wrote in message
news:[email protected]...
> Hardcore Icon wrote:
> > Working on a paint job on my Formica counter top (primer, granite spray
> > paint, and polyurethane finish).
SNIP
> Yes.
>
> 320 wet-dry on block, wet, with mineral spirits. Takes about
> 2 minutes to wet sand a 1 x 3 foot bookshelf between coats.
> Wet paper cuts _fast_, like an eraser. Hardest part is not
> sanding through.
On Wed, 10 Jan 2007 22:42:50 +0000, Hardcore Icon wrote:
> Working on a paint job on my Formica counter top (primer, granite spray
> paint, and polyurethane finish). This is the first time I've used
> Polyurethane and I'm getting different directions from different sources.
>
> My question for anyone who would know:
>
> Do I need to sand between coats of Poly?
>
> I'm going for 4-6 coats, have the first coat on and dry, and am not sure if
> I should sand or not. The directions on the can say "recoat in 6 hours. If
> first coat is allowed to dry 48 hours, sanding is necessary between coats."
>
> Does this mean if I don't wait 48 hours that I do not need to sand?
>
> Thanks in advance for any help.
Generally speaking do what the coating manufacturer says, not what some
self-proclaimed expert says unless it's more conservative.
In the extant case, if you recoat in less than 48 hours you don't need to
sand. I would anyway if I were going for a good finish--the smoother the
surface the better the finish.
> Icon
--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)
On Wed, 10 Jan 2007 18:47:51 -0500, bent wrote:
> Is there not the concern that the finish has to completely harden before
> sanding? I would think (w/ nothing to back it up) the longer the
> better. For the sake of the after-sand finish quantity/quality. Like
> multiply x 5 to be safe. Fives a good average number for things like
> that in general, any opinions? Quit asking questions, you're confusing
> us.
If the finish has to completely harden before sanding then I'd start using
a different product. The precatalyzed lacquer I've been using lately is
ready for sanding in 40 minutes (per the manufacturer) but not completely
cured for several days.
The main issue with sanding is whether it is hard enough to sand without
prematurely clogging the sandpaper or otherwise misbehaving. I can't see
where waiting a week between coats is going to gain anything.
> ----== Posted via
Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet
> News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the
> World! 120,000+ Newsgroups ----= East and West-Coast Server Farms -
> Total Privacy via Encryption =----
--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)
On Sat, 13 Jan 2007 05:17:39 GMT, Lew Hodgett
<[email protected]> wrote:
>Steve wrote:
>
> > Watch out for steel wool filings and water-based finishes. It's a
>bitch
> > getting rid of the rust spots.
>
>SFWIW, that's why bronze wool is out there.
As well as synthetic rubbing pads.
Great.
I've got all kinds of sandpaper and steel wool too just in case I need it,
but going to try a couple coats without sanding and see where it leads me.
We'll see......
Icon
"Bewildered" <[email protected]> wrote in message
news:J%[email protected]...
>
> "Hardcore Icon" <[email protected]> wrote in message
> news:[email protected]...
>> Working on a paint job on my Formica counter top (primer, granite spray
>> paint, and polyurethane finish). This is the first time I've used
>> Polyurethane and I'm getting different directions from different sources.
>>
>> My question for anyone who would know:
>>
>> Do I need to sand between coats of Poly?
>>
>> I'm going for 4-6 coats, have the first coat on and dry, and am not sure
>> if I should sand or not. The directions on the can say "recoat in 6
>> hours. If first coat is allowed to dry 48 hours, sanding is necessary
>> between coats."
>>
>> Does this mean if I don't wait 48 hours that I do not need to sand?
>>
>> Thanks in advance for any help.
>>
>> Icon
>>
> That is correct; if you recoat quickly the new coat can bond. If you wait
> you have to rough the surface up a bit.
> I like to put on a few coats, sand (well, steel wool) and then put on my
> final coat.
> The more often you sand, the better chance you have of getting a smooth
> final surface. But it is work and makes for a thinner coating.
>
Thanks John!
Maybe I'll hit it just a little bit with some 220, it hasn't been 48 hours
but if it will make a better finish then that's what I'll do. But the
directions only said to sand if it's passed 48 hours so going by that I
guess I don't *have* to sand.
Thanks again,
Icon
"J. Clarke" <[email protected]> wrote in message
news:[email protected]...
> On Wed, 10 Jan 2007 22:42:50 +0000, Hardcore Icon wrote:
>
>> Working on a paint job on my Formica counter top (primer, granite spray
>> paint, and polyurethane finish). This is the first time I've used
>> Polyurethane and I'm getting different directions from different sources.
>>
>> My question for anyone who would know:
>>
>> Do I need to sand between coats of Poly?
>>
>> I'm going for 4-6 coats, have the first coat on and dry, and am not sure
>> if
>> I should sand or not. The directions on the can say "recoat in 6 hours.
>> If
>> first coat is allowed to dry 48 hours, sanding is necessary between
>> coats."
>>
>> Does this mean if I don't wait 48 hours that I do not need to sand?
>>
>> Thanks in advance for any help.
>
> Generally speaking do what the coating manufacturer says, not what some
> self-proclaimed expert says unless it's more conservative.
>
> In the extant case, if you recoat in less than 48 hours you don't need to
> sand. I would anyway if I were going for a good finish--the smoother the
> surface the better the finish.
>
>> Icon
>
> --
> --John
> to email, dial "usenet" and validate
> (was jclarke at eye bee em dot net)
Thanks for the info Lew!
Glad I found this NG.
Icon
"Lew Hodgett" <[email protected]> wrote in message
news:[email protected]...
> Hardcore Icon wrote:
>
> <snip>
> > The directions on the can say "recoat in 6 hours.
> > If
> > first coat is allowed to dry 48 hours, sanding is necessary between
> > coats."
> >
> > Does this mean if I don't wait 48 hours that I do not need to sand?
> <snip>
>
> Yep.
>
> After 48 hours, you no longer get a chemical bond so you have to sand to
> get a mechanical bond between coats.
>
> Pretty much standard for LP.
>
> Why not talk to the factory for latest update.
>
> Lew
>
Hardcore Icon wrote:
> Working on a paint job on my Formica counter top (primer, granite
> spray paint, and polyurethane finish). This is the first time I've
> used Polyurethane and I'm getting different directions from different
> sources.
> My question for anyone who would know:
>
> Do I need to sand between coats of Poly?
>
> I'm going for 4-6 coats, have the first coat on and dry, and am not
> sure if I should sand or not. The directions on the can say "recoat
> in 6 hours. If first coat is allowed to dry 48 hours, sanding is
> necessary between coats."
> Does this mean if I don't wait 48 hours that I do not need to sand?
>
> Thanks in advance for any help.
>
> Icon
Duhhhh, do you suppose that's what it says?
Reason to sand: Air is not dust free; can see dust particles.
Reason not to sand: In specs per the directions and surface looks perfectly
fine, no dust, bubbles or other contminants visible.