Strange deposit on sanding belt?

[Mark A]

I'm sanding off the paint from an old chest to expose the bare wood beneath, but every 20 seconds or so I have to stop, scrape off the deposit from the belt and clean it with a latex block.

I started with an 80 grit belt and then a 60 grit but they clogged up too quickly, so now I'm using a 40 grit belt. The belt in the pictures was brand new, and used for perhaps 15 seconds.

Any idea what it is, and what I can do about it?

Cheers,
Mark

 

[Wildman]

wax polish?
maybe a solvent wash before sanding

 

[pro-joiner]

Sander is probably melting the paint/wax/varnish causing it to clog up the belts.

 

[Blister]

I would try a cabinet scraper first then sand it

 

[Mark A]

Sander is probably melting the paint/wax/varnish causing it to clog up the belts.

The sander was on it's slowest setting, I was using light pressure and I always kept it moving. It was also connected to a vacuum so I don't see how it would be able to generate that much heat when used like this?

 

[Hardwood66]

I would try a cabinet scraper first then sand it

+1 for scraping first

 

[Hudson Carpentry]

Very common. Could be caused by many things and always avoided by scrapping the piece first.

 

[Racers]

Hi,

I have been removing water based varnish from cupboard doors I found it much faster to scrape the varnish off.
It was clogging the sander, and you don't have to wear a mask and ear defenders.

Pete

 

[Jacob]

It'll be gesso of one sort or another i.e oil paint with lots of chalk filler and probably lead pigment. Is it heavy? It's a dense primer for finishes such as wood effect graining.
I wouldn't use a sander anyway on old paint. Blow lamp first, followed by hot air gun, followed by paint stripper.

 

[Richard T]

Yup - it's paint. It will clog any abrasive very quickly. Best to scrape or strip or both first.

 

[Elapid]

I got a pine farmhouse type table given to me covered in yacht varnish. My belts looked the same after sanding it off.

 

[mn pete]

My guess is many layers of old wax?

 

[Mcluma]

Its normal, its wax / paint / varnish

Your belt is actually still good to go, but what you need to do is buy these sticks to clean the belt

the sticks take all the crap out of the belt and its like new again

 

[Mark A]

I was referring to the band along the edge which feels like set gripfill! I've got one of those latex blocks, which is usually great for cleaning the belts but useless for this. I ended up sticking an old axe in the vice and running the sander against the edge to scrape of the deposit.

We used to have a hot air gun but I can't find it. I might try the car boot sale on Saturday.

Thanks for the advice,
Mark

 

[Jacob]

Basically, sanding is about the worst possible way to remove thick old paint.

 

[AndyT]

We used to have a hot air gun but I can't find it. I might try the car boot sale on Saturday.

Only £9 at Screwfix - go on, spoil yourself! :wink:

http://www.screwfix.com/p/direct-power-2000w-heat-gun-240v/89200

 

[Mark A]

Only £9 at Screwfix - go on, spoil yourself! :wink:

http://www.screwfix.com/p/direct-power-2000w-heat-gun-240v/89200

That wasn't in the Screwfix catalogue when I called in today!!!

I've just bought an Earlex from Toolstation for £24 #-o