Sanding Painted Trim

[DanMcDan]

Hello,

I need to sand some painted Colonial door casing in my 1970 era home prior to a paint touch-up.  I know I could use a soft sanding block, but was hoping there might be a faster way with one of my three sanders - Rotex 150, ETS 125 EQ or RTS 400.  Most of the dings go through to bare wood.  I was hoping a soft pad and some Granat might do the trick?

In another thread I read someone's suggestion of making a custom sanding block from auto body filler.  I would take that as an alternative to a machine based solution, but am not sure how to do it!

Thanks!

 

[AlexThePalex]

Depends, does your door trim have a lot of profile? You can use your 3 sanders for the flat parts, but if there's a lot of profiles I see a lot of hand sanding.

 

[huntdupl]

Welcome to FOG

Out of that lineup, the RTS is your best bet to remove most of finish as your prob working with lead paint so a CT is your friend. I wouldn't try to sand the dings out but rather fill them, and if you're going to buy some Bondo, may as well use that. Just be sure to work with small batches at first if you've never worked with it before. Climate plays a big part in how quickly it drys - warm weather=quicker curing and maybe you'd start with the recommended amount of harder but I've always found it to be much much less. One other tip when applying bondo is to 'green' sand, that is, don't walk away and let it harden up fully, let it sit a minute an remove the bulk of excess fill while its still a bit rubbery, this will sand you a lot of elbow grease. You may/may not fill the hole completely in one pass so don't try.

If you're dealing with somewhat ornate trim etc, an oscillating multi tool such as Fein would be a wise investment - especially if you foresee more restoration in your future. Their profile sanding set is impossible to beat even with a cheap Harbor Freight sander. Huge time saver on windows etc.

As for creating a sanding block, this is relatively new for me as well, you need to recreate the existing casing profile say 5" long. (this should allow you to use quarter sheets of paper, covering a trim with between 2-3.75") The idea is you build a shallow box around that 5" length of recreated profile and pour bondo in to make a negative. This negative is removed, covered in sand paper which contours to the existing door casing. I think worth the time if you have a lot to sand, but something to keep in minf with those old houses is that nothing is exactly the same as it if were built yesterday.

I'd power sand, fill holes/dents, prime, sanding block, refinish. Make use of the right paper and speed to avoid gum up of sanding disk.View attachment 1

 

[huntdupl]

Now I remember, I just saw that in Fine Woodworking
View attachment 1

 

[live4ever]

Now I remember, I just saw that in Fine Woodworking
View attachment 1

Cool tip! 

 

[DanMcDan]

Thanks all for the ideas.  I guess I was hoping there was some way to take a thick polishing pad for the rotex, somehow attach a 3200 grit granat disk and go at it in aggressive mode to smooth the dings down.  But it doesn't sound like that would work... [huh]

Great idea for custom sanding block - except I have no spare trim!  [eek]

I like best (of the options thus far) to fill the dings rather than sand down to them.