Wet sanding and wood swell

[Darren Galloway]

I have always wet sanded my final finishes. I have never had a problem with the wood swelling before. I was wet sanding a basswood solid body and noticed after I was finished that the wood around the pickup cavity started to swell from the moisture. I know I should had used mineral spirits or another medium to wet sand with but like I said I have done this a lot and never had issues. Of course I have never used basswood for a body before. Anyway, here is my question: Has anyone ever experienced this and will it go down as it dries or do I have no choice but to sand it back down?

[Mario Proulx]

Walk away; it should be fine, given a week or so.

[Mark Swanson]

Basswood is quite porous, and if it isn't sealed well in the holes and cavities the open grain there will suck in water big time. It does make a great sounding solid body though!

[Darren Galloway]

Went out to the shop and checked on it. Looks like it is already going down. I'm going to give it a week and see what happens before I mess with it. Thanks fro the tips.

[Darren Galloway]

Went out this morning and the finish is almost back to normal. Looks near perfect. A true lesson in patience. Glad I didn't give in to my "do something" urge and waited.

[David King]

Darren,
Are you raising the grain as part of your final sanding before finishing?

[John Sonksen]

I would always make sure to let any water swollen wood completely dry before sanding it. If you sand it while it's still wet, when it eventually dries it can drop down below where it was leveled to while you were sanding it and leave a depression. I just saw this happen to a whole bunch of cabinet doors at my shop. The door guy ran them through the widebelt before the joints had cured all the way and when we went to paint them every single joint had shrunk and now we have very prominent lines where the stiles and rails meet.

[Warren May]

Darren,
I had exactly the same thing a few months ago...not sure the post is still active. Basswood body with black nitrocellulose and several coats of clear. I let it dry for a week before sanding any further. Like you say, I've never had problems when sanding other woods and I think basswood must be especially susceptible to it. My swellling went down but being black it was noticeable in a place or two and there were some depressions/dimples so I shot another round of clear after it dried and everything looked presentable. Everyone had the same warnings about wetsanding but I'm inclined to believe basswood is particularly bad about swelling which, at least to me, makes sense due to the way its fibers are arranged. Also, basswood seems to be a catchall category for lots of different types of wood.

Hold it up to some strong light to make sure you don't still see some swellling or depressions. Black on mine was particularly unforgiving.

[Darren Galloway]

Darren,
I had exactly the same thing a few months ago...not sure the post is still active. Basswood body with black nitrocellulose and several coats of clear. I let it dry for a week before sanding any further. Like you say, I've never had problems when sanding other woods and I think basswood must be especially susceptible to it. My swellling went down but being black it was noticeable in a place or two and there were some depressions/dimples so I shot another round of clear after it dried and everything looked presentable. Everyone had the same warnings about wetsanding but I'm inclined to believe basswood is particularly bad about swelling which, at least to me, makes sense due to the way its fibers are arranged. Also, basswood seems to be a catchall category for lots of different types of wood.
Hold it up to some strong light to make sure you don't still see some swellling or depressions. Black on mine was particularly unforgiving.

Yes mine is black too. But I think it's going to be ok. I am waiting a while before I do anything with it. I want to make sure it's stable. Thanks for the tip I will look very closed at it.
Yes I did raise the grain David but it still swelled. Like I said, never had trouble before. I agree with Warren, I think it was the basswood. I've never used it before. Touchy stuff it saeems.