Managing Dust by HC120226094542

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									           --------------COMMLINE--------------
                The newsletter of Advanced Re-enameling Systems

                                    16-10-01

                                    Issue 4
                               Managing Dust


Possibly one of the most irritating surface defects is dust particles caught in the new
surface. It makes the bath re-enamelling work look like an amateur “paint job”. The
visual impression is almost as uncomfortable as the tactile (sense of touch) impression.
While some customers expect and accept some imperfections they are usually sensitive to
and intolerant of this one, and quite rightly so in my opinion. This is probably due to the
fact they are accustomed to bath fixtures being smooth for hygiene purposes so this
“rash” runs against the accustomed grain.

So how do we deal with this infection: unfortunately there is no quick fix or one thing
that you can do to handle it because the dust motes can arrive from a verity of sources.
The way I handle it is to reduce the unwanted effects by addressing a number of its
causes and tackling it when it occurs and after it has hardened in. Essentially you have to
work at it from the beginning of the job to the end. If procedures are correctly applied in
the early stages of the work no post cure work will be needed. In a clean environment a
good bath re-enameller can get his surface on and dried with no dust but on average will
get only about six inconsequential motes per bath requiring no further attention. If this is
your standard there is no need to read further but do send me your tips.

It can take a lot of time going over a dusty bath trying to remove the dust from it when it
has cured. Sanding and polishing the new surface is not optimum because:

       1. Sanding and polishing reduces the coating film thickness, weakening its
performance.

       2. You never regain the same "off the gun wet look finish".

       3. It takes work and time.

       4. You can splatter polish about the place and give yourself a further clean up job.

We build dust reduction into our procedure by integrating the various actions into the
basic checklist. This seems to work well as important steps are never missed and you just
get into the habit of doing it all without thinking.

Here are the actions

It is important to firstly decide before doing the bath that you are going to do all you can
to get a dust free finish, get your attitude aligned to doing it.
The next action is to make sure that any other work that is dust causing has been
completed or at least suspended for the time you are working. You are going to have
trouble getting a clean finish if there is a carpenter outside the door running a band saw.
Don’t laugh, it has happened!

Next, make sure your dustsheets are not “dustysheets” that create a cloud of dust when
you open them up. They are best shaken out before bringing them into the house. If it is
raining leave them outside to get damp. I always prefer damp sheets – it keeps the dust
down.

When you have cleaned the bath and washed it down with clean water put the plug in and
fill the bath with hot water until the room is steamed up. This will damp down dust on the
walls etc. so that it stays put and does not float about. Bring in your other gear while it is
steaming up.

If there has been construction going on in the bathroom and there is loose plaster, or
anything that looks like it may emit dust, wet it and mask it with paper, sheets or plastic
film. A recently plastered wall should be hosed down so it is wet. The plaster will dry as
you prep and will be damp when you start spraying.

While masking have your turbine to hand to blow out dusty cavities around the bath that
might blow out dust while spraying.

Cover the floor and fixtures with damp dustsheets or damp your dry sheets before
spraying. I keep my sheets damp and heavy by wetting them a bit before each spraying.
You really need a plastic hose that can fit over a tap so that water can be sprayed around
the bathroom.

If there is no carpet and the flooring is being replaced and is dusty, sprinkle water all over
it and make sure it is damp. This holds the dust down. It is better to put down your damp
sheets even if overspray is not a problem as it will hold the dust down

After applying Permabond bonding agent give the bath a tack out. Tack rags are best
fully opened out when taken out of the packet, they are more effective for a longer period
of time this way.

Have the window open while spraying. Dust can come in and spoil your work so do not
open it too wide.

Wear a paper hood while tacking and spraying. This prevents material landing in your
hair and stops the bits falling out of your hair into the bath.

It is best to carry out the spraying in lighting conditions which are as good if not better
than they will be when the bath is put back into use. Baths that are spot lit are the most
challenging to do since surface anomalies will be easily seen when the job is complete.
We have a dedicated halogen light for times when lighting is poor.

Before you spray the bath, and before you tack it out, run the air hose from the turbine, along the join
between the masking and the bath. This flushes out loose dust that may blow out during spraying.

Have a separate set of overalls for spraying (paper spraying overalls are best but not essential. If you only
have separate boiler suit damp it down with water before you tack the bath out.)

Apply a full coat of Interface 2 enamel primer to the bath, unclip the gun from the hose
and blow the room down especially any cobwebs or dusty cracks or openings around the
bath. Then lean the hose over the bath and let the hot air blow over the bath while you
make up the topcoat. Fixed ventilation fans above the bath can cause problems if they
have dust caught in them. The mist in the room can pull it down into the bath; blow them
out before spraying the top coat. You want to stir up any remaining dust before you start
working with the topcoat.

Don't smoke in the room during or after spraying.

Portable extractor fans can reduce dust by drawing the air quickly out of the room but if
they are not kept clean they can create more dust than they get rid off. I find I can vent
the room of suspended spray fog by blowing the hose in the direction of the window and
pushing it out this way. I do not however attempt to vent the fog from the enamel primer
because this fog cleans the air like a fall of snow by pulling floating dust down onto the
damp sheets.

Before making up your topcoat check your gun over for dust or flaking enamel – believe
it or not a lot of mess on the surface arrives there from the gun itself!

When you return with your coating mixed in the pot, turn the turbine off and lightly scuff
the bath down with dry 500 3M wet n dry paper, making sure you cover every bit of the
bath. Do not go right through the Interface. Then tack it out very thoroughly starting at
the top of the bath and working your way around and down until the dust is collected in
the base and then get this out. THIS IS THE MOST IMPORTANT STEP IN
REDUCING DUST DO IT COMPLETELY, FANATICALLY AND METICULOUSLY,
IT WILL SAVE YOU LOTS OF TIME, FRUSTRATION AND MONEY.

When you turn your turbine on make sure that the gun is connected and that the gun is
pointed down, you do not want to blow the room anymore otherwise it starts air
movement in the room which can dislodge dust.

Make sure you run your hand over the gun to make sure it is dust free.

Spray on your topcoat in the least time possible. All the time the surface is wet it is at risk
so get your coating on and flashed off in the minimum amount of time but without
rushing. Naturally our two coatings Vitroglaze III and Isofree work well in this respect.
The flash off can be accelerated in a number of ways; having the bath warm and blowing
it over with the hot air between coats are two ways.

Keep a pair of pointed tweezers handy so that if any dust lands in the bath while spraying
you can lift it cleanly off the surface. This is best done when you see it, as it can be
difficult to find later. Also carefully check over the complete surface between coats by
using your hand to reflect light to its various parts then picking off any dust motes found.
Set the air cap on the spray gun to a spot spray rather than an open fan. Spot in the holes
produced by lifting out dust motes and spot out the motes too small to be removed.

Use a coating which has a high build (high build means it can go on thick without
sagging). This means you can cover the dust with material, burying it so that it cannot be
seen or felt. After the last coat overwhelm any remaining moats with the spot out
technique.

When you have finished spraying leave the room alone for a few minutes until the
surface has dried. Do not at this point leave the hot air running.

After the mist has dissipated, very gently remove the dust sheets by pulling them together
without lifting them up – keep them low and drag them out at floor level.

Get out of your spray overalls.

The bath surface should skin up before you try removing masking from around it. There
is a technique for removing the main masking from behind the bath that prevents things
dropping in it but it is a bit difficult to explain without a demonstration. Essentially you
are pulling it and curling it around at the bottom to form a shelf that can collect anything
that falls of the wall.

If something does land on the bath you can get it off by lightly touching it with a bit of
masking tape. The dust will lift it off as long as the tape is stickier than the bath.

Do not let the customer vacuum clean the room as soon as you leave as this kicks up dust.

Once the surface has fully cured the simplest way to get rid of protruding dust that is
caught in the surface is with an old style razor blade. One does have to master the
technique but once you have, it does bypass the need to flat and polish.

Only in really extreme situations should it be so bad that the solution is to flat and polish.
Using 1200 wet n dry followed with machine buffing with a cutting or rubbing compound
and finally polishing with a wax polish will redeem it.

Well I hope you got something out this.

Best of luck.
Ian Milton

								
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