Sanding to perfection

[stag36587]

So, having got my 2 door back on the road for the first time in 20 years I'm thoroughly enjoying driving my first minor.

When restoring the car I spent quite a bit of time trying to get the bodywork as good as I could but in all honesty it needs more work. I'm just not happy with the smoothness of some areas after repairs - especially the outward curves at bottom of doors and quarter panels.

My plan is to rub down again and try and get a smoother finish. My question is what is the best way to sand those curved areas - e.g. By hand or with orbital sander? Maybe I should make a curved sanding block to the same contour as the body?

Would be interested to hear from those who have carried out repairs in these areas.

Many thanks

[RobThomas]

Ali TIG-welding rods make good 'profiles' for shaping. I found that a long board was better for getting one-dimensional curves right.

I must admit I've never been able to feel the imperfections after years of riveting aircraft and then some extensive hand surgery so I get someone else to do the finishing before painting.

[GBond]

You'll get the best results sanding by hand with the longest sanding block you can easily manage and high quality sandpaper (3M is very good). You'll need lots of patience.

Use also a good base coat and as little filler as possible.

After painting, you can use Trizact in 3000 grit or even 5000 this time on an orbital machine with water to get rid of all the orange peel and the paint will look amazing.

[bmcecosse]

Don't use 'sandpaper' - very fine 'wet & dry' is what you need. But will the surface not improve with just polishing mop and good cutting compound?

[stag36587]

Don't use 'sandpaper' - very fine 'wet & dry' is what you need. But will the surface not improve with just polishing mop and good cutting compound?

Yes indeed has made a significant difference to most of the car thanks, so it's only localised areas that need more work

[GBond]

3M calls it "sandpaper" so yes, something like this should work:

http://3mcollision.com/3m-wetordry-sand ... -grit.html

For the bottom of the door you'll get better results holding the block horizontally and sanding up and down, start with 180 if you need to remove a lot of filler or sealant, then go to 320, 400 and 600 right before painting the color.

This is assuming you mean to repaint.

If your intention is just getting the existing paint to shine more go for the Trizact foam discs (3000, then 5000) on an orbital sander, with some soapy water before a two or three stage buffing and you'll get that deep flat look.

[colin addison]

For the inward curve you need a round something to wrap the wet'n'dry round, like a loofa, or similar. It should have some spongy property. Don't use it straight up and down, try to use it varying the angle so that you don't "track". Be very careful of the sharp bend at the door bottom, keep off it or you will sand through the paint rapidly. Use light pressure, particularly when the paper is new. 800 or 1000 grit is good for the last sanding stage. Not many cars had large inward curves back in the day, so sanding sponges tend to be unavailable in rounded shapes.
all the best.
Colin

[RobThomas]

Pipe lagging tubes or the ones used for swimming pool flotation aids are good options.

[stag36587]

Thanks for the suggestions and advice guys, I'll have a good go over the next couple of weeks or so.