How can I fix these blotches on this table I am restoring?

[redbackspider77]

I am restoring an old table which has a really unsmooth tabletop, so I started with sanding. However, after 5 passes with P80 using my orbital sander, blotches remain from the previous stain. What can I do to fix these?

[JacobZ]

Hi @redbackspider77,

This looks to be a penetrating sealer, meaning it soaks into the timber fibres and penetrates below the surface. The only way to remove it is to keep sanding till you remove the affected timber fibres.

The short and sweet answer to your question is to keep on sanding. 

You could try using some 40-grit sandpaper before smoothing it out with a finer grit, or use a stronger sander, such as a belt sander, to help speed up the process, but outside of this, it is all down to persistence.

Let me know if you have any further questions.

Jacob

[redbackspider77]

Thanks for your reply.

How about paint stripper, particularly Polystrippa? Could that work? I believe I may have simply melted the finish deeper into the wood while sanding.

[JacobZ]

Hi @redbackspider77,

You could certainly give it a try, but if it has penetrated deep into the timber, I'm not positive it would work.

It can't hurt to try, though.

Jacob

[redbackspider77]

Also, don't you think 40 grit will leave scratches that are very tough to remove?

[MitchellMc]

The key point is that 40 grit is only ever a temporary, problem-solving grit, not a finishing grit @redbackspider77. Its job is to remove material quickly, especially stubborn coatings like this, not to leave a surface ready for coating.

If you do use 40 grit, keep it controlled and brief, apply light to moderate pressure, keep the sander moving, and stop as soon as the blotching is gone. Once that happens, you then step back up through the grits methodically. For example, move to 80 grit to remove the 40 grit scratches, then 120, then 180, and possibly 220 depending on the finish you plan to use. Each grit’s job is only to remove the scratches from the previous grit, not to reshape the surface again.

Mitchell