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Wood finishing tips, rubbing, sanding, stripping and problems with aerosols



 

WOOD FINISHING TIPS

RUBBING

When rubbing a high gloss finish to
remove over spray, orange peel, or as in repair to renew a gloss, I some
times see scratch patterns through the shine. What causes this?

If you started
the job with fine sand papers, and skip grades, you can leave sand paper
scratch patterns behind that the compounds can’t remove.

If you start with 400 grade, go next to
600 grade, and then to 1200 grade before moving on to the compounds.

If
you’re not familiar with “Micro Mesh” sand pads, check them out,
as they are made for working up high gloss finishes in spot repair work.
They are a must for polyester finish repair.

It’s also possible, when
working through a series of compounds, that you start with an aggressive
grade and skip lesser aggressive grades before going to a polishing grade
for the high gloss. That would be apparent if you see swirl patterns
through your gloss.

PROBLEMS ENCOUNTERED WHEN
USING AEROSOL SPRAYS

Aerosol won’t spray.

1. For heavily pigmented products. Cause:
Depressed spray tip before ingredients were properly agitated. Pigmented
materials settle to the bottom and, if not thoroughly mixed, can plug the
spray valve stem and tip preventing proper functioning. Thorough agitation
before using is essential.


2. For general aerosol products. Cause: Propellant has leaked from can or
valve stem has disconnected from valve when can was pressurized. Test for
disconnect by inverting can – it will spray in this position if stem has
disconnected.


Aerosol can sprays but spits.

Cause: Can was not thoroughly agitated
before using. Hold can inverted and clear valve. Shake thoroughly and
proceed. 

Or: 

Can is cold. A cold temperature reduces
pressure inside can and prevents proper atomisation. Warm can to 18
degrees C minimum e.g. by partially placing can in warm water. Do not use
direct heat! 

Or: 

Spraying can continuously for prolonged
period cools ingredients inside causing a reduction of pressure. As you
feel can surface becoming cold, stop and allow it to warm up.


Aerosol finish turns milky white.

Cause: Blushing (moisture entrapment in the
film) occurs during warm rainy weather and hot and humid periods. If
whiteness appears, spray over the finish with
Blush Eraser to open the
film and allow moisture to escape. 

Or: 

Oil, wax or other incompatible contaminant
on the surface can lead to a cloudy appearance in the finish. This can
appear quickly or may be a delayed reaction. Always thoroughly clean the
surface to be sprayed with De-Waxer 741.


Aerosol fisheye’s (craters) in the finish caused by silicone
contamination.

If you suspect a finish may have
contamination, thoroughly wash the area to be coated with Wood Stain
Reducer. If problem persists, apply a light coat of Shellac.

PREPARATION

My stripper isn’t working.

Not enough time is allowed for chemicals to
work. 

Or: 

The stripper is not strong enough. 

Or: 

The stripper may not be the right one for
the job. Allow more time for the stripper to work. Get a stronger
stripper. Check to see if the stripper only removes certain finishes.
Latex and waterbase finishes are not removed by all strippers, check the
label/directions.