Thursday, March 25, 2010

Taking the rough with the smooth - buying abrasives.

If you never have to rub down paint you can skip this and wander off to read granny buttons or no problem or whatever. Otherwise read on and take heed.

I spent the whole morning trying to source sanding discs. I've decided that abrasives can be very wearing and now I feel rough and flat at the same time. The story goes like this.

According to my notes from Phil Speight's painting course, if you are repainting over sound old paint (having fixed any local blemishes or rust spots), you need to:

Rough the surface of the old paint with 80 grit paper
Apply new undercoat(s) if changing colour
Flatten the undercoat to get a smooth surface using 240 grit paper
Apply gloss coats, rubbing down penultimate coat with 500 or 600 grit paper, then lightly go over with 1000 grit paper.
Then put on your wonderful top coat of paint
Stand back and admire.

Do most of the rubbing down using a random orbit sander connected to a vacuum cleaner.

"What's difficult about that?" you ask. You can get sanding discs anywhere.

I'll tell you what's difficult. Getting paper above 320 grit that will fit my (quite ordinary) sander. That's what. Especially in bulk, and without buying expensive mixed grit packs.

No local supplier could help, not even autofactors. I think if I had a rectangular sander that could take sheets or paper off a roll I might have done better, or if I had a big professional 150mm sander. My sander uses standard DIY 125mm velcro backed discs with 8 suction holes. Quite a common format, but not it seems for very fine grade papers.

What is also difficult is knowing how much I will need. I rang Phil Speight and all he could say was "Well it all depends on the condition of the paint etc. We just have a huge box and use what we need." I did manage to deduce that I would need quite a lot.

Eventually I found a source of 600 grit discs on ebay although they have no holes, so I'll have to puncture them through with a pencil once mounted on the sander.

I also bought some more of those scotchbrite discs, this time called non-woven discs, and some natty looking abrasive cloths a bit like the green scratchies we use for dishwashing, but in much tougher grades. They should be handy for getting into corners and inside the deck drain gutters.

For all except the 600 grit papers, but including the non woven discs and cloths the best place I found was, although of course I haven't received the goods to inspect yet. They had a very good range of stuff of all types, at good prices and free delivery.

If I haven't bought enough, we'll have no time to order more once we're in the wet dock. By the time we have it all in,and taking into account what I've already bought, we'll have spent well over £60 on abrasives.

1 comment:

Sarah said...

I like 'scratchies'. We call them 'scritchers'.