JC

Jay Chan

23/05/2007 9:35 AM

Spray Painted Surface Very Rough

I used cans of semi-gloss oil based spray paint to spray the finish
coat on a book case. The surface was very smooth before I sprayed.
But the sprayed surface was very rough after spraying. Seem like
spray paint droplets might have combined together in mid air before
landing on the surface. I used 400 grit sand paper to easily sand out
the rough surface. Now the surface is flat instead of semi gloss
after the sanding. My questions are:

1. How should I prevent this problem from happening again?

2. How should I put back the shine on the surface to something like
semi gloss?

3. How should I put a protective coating on the "flat" surface to
allow me to clean the surface easily?

Thanks in advance for any info.

Jay Chan


This topic has 5 replies

pp

pumis

in reply to Jay Chan on 23/05/2007 9:35 AM

24/05/2007 1:25 AM

It sounds like the nozzle wasn't clean enough.
This can cause globs on the finish that don't
flow into the surface and settle with the rest of
the spray.
Wetsand with 600 grit, clean , dry, wipe and spray
again.
It's alot of extra work but it will turn out the way you
want it too.

been there, done that.

JC

Jay Chan

in reply to Jay Chan on 23/05/2007 9:35 AM

24/05/2007 9:36 AM

On May 23, 2:49 pm, [email protected] wrote:
> On May 23, 12:35 pm, Jay Chan <[email protected]> wrote:
>
> > I used cans of semi-gloss oil based spray paint to spray the finish
> > coat on a book case. The surface was very smooth before I sprayed.
> > But the sprayed surface was very rough after spraying. Seem like
> > spray paint droplets might have combined together in mid air before
> > landing on the surface. I used 400 grit sand paper to easily sand out
> > the rough surface. Now the surface is flat instead of semi gloss
> > after the sanding. My questions are:
>
> > 1. How should I prevent this problem from happening again?
>
> > 2. How should I put back the shine on the surface to something like
> > semi gloss?
>
> > 3. How should I put a protective coating on the "flat" surface to
> > allow me to clean the surface easily?
>
> > Thanks in advance for any info.
>
> > Jay Chan
>
> What is the source of the roughness? Paint fragments or small
> wood fibers that popped up from the surface?
>
> You may well have "raised the grain"- caused such small fibers
> that remain after sanding to stand proud after getting wet.
>
> Were that so, I'd be sure to use a cabinet scraper (rather than
> any sander) prior to sealing and between subsequent coats.
>
> Can easily pass the "baby's bottom" test, doing that, with- Hide quoted text -
>
> - Show quoted text -

The roughness was definitely from the spray paint, not from raised
wood fibers. The roughness from raised wood fibers would have taken
me a long time to sand them away. On the other hand, sanding out the
roughness from spray paint was quite easy (the only downside was that
sanding also removed the shine from the paint, and I will fix this by
using wipe-on-poly).

I have put multiple coats of oil based primer over the surface;
therefore, I don't have the raised wood fibers issue any more.
Moreover, the spray paint is also oil based.

Thanks for pointing out the possible cause of the roughness though.

Jay Chan

JC

Jay Chan

in reply to Jay Chan on 23/05/2007 9:35 AM

24/05/2007 9:39 AM

On May 24, 4:25 am, pumis <[email protected]> wrote:
> It sounds like the nozzle wasn't clean enough.
> This can cause globs on the finish that don't
> flow into the surface and settle with the rest of
> the spray.
> Wetsand with 600 grit, clean , dry, wipe and spray
> again.
> It's alot of extra work but it will turn out the way you
> want it too.
>
> been there, done that.

I didn't think of that. Now that you have mentioned this, I will
clean the nozzle right after each use next time when I need to spray
paint from a can. Thanks for the tip.

Jay Chan

Lr

"Leon"

in reply to Jay Chan on 23/05/2007 9:35 AM

23/05/2007 11:41 AM


"Jay Chan" <[email protected]> wrote in message
news:[email protected]...
>I used cans of semi-gloss oil based spray paint to spray the finish
> coat on a book case. The surface was very smooth before I sprayed.
> But the sprayed surface was very rough after spraying. Seem like
> spray paint droplets might have combined together in mid air before
> landing on the surface. I used 400 grit sand paper to easily sand out
> the rough surface. Now the surface is flat instead of semi gloss
> after the sanding. My questions are:
>
> 1. How should I prevent this problem from happening again?
>
> 2. How should I put back the shine on the surface to something like
> semi gloss?
>
> 3. How should I put a protective coating on the "flat" surface to
> allow me to clean the surface easily?
>
> Thanks in advance for any info.
>
> Jay Chan
>

Sounds like you may have put the coat on too thin/dry.

dd

"dadiOH"

in reply to Jay Chan on 23/05/2007 9:35 AM

24/05/2007 5:54 PM

Jay Chan wrote:
> On May 24, 4:25 am, pumis <[email protected]> wrote:
>> It sounds like the nozzle wasn't clean enough.
>> This can cause globs on the finish that don't
>> flow into the surface and settle with the rest of
>> the spray.
>> Wetsand with 600 grit, clean , dry, wipe and spray
>> again.
>> It's alot of extra work but it will turn out the way you
>> want it too.
>>
>> been there, done that.
>
> I didn't think of that. Now that you have mentioned this, I will
> clean the nozzle right after each use next time when I need to spray
> paint from a can. Thanks for the tip.

Don't clean it by poking something in it, clean it by holding the can
upside down and depressing the valve until only propellant (no paint)
comes out. Like it says on the can.


--

dadiOH
____________________________

dadiOH's dandies v3.06...
...a help file of info about MP3s, recording from
LP/cassette and tips & tricks on this and that.
Get it at http://mysite.verizon.net/xico



You’ve reached the end of replies