Wet Sanding help...

[Audiowonderland]

How do you keep water out of the holes when wet sanding?

 

[stratamania]

Which holes?

 

[bagman67]

If you're talking about the pilot holes for screws, you can plug them with some wax to keep water from getting in there.  No need to pack the entire screw-hole, just enough to block the water from getting in.  And no need to worry about cleaning out the wax, since it will then serve as a lubricant for screws. 


If you are talking about exposed wood areas like a neck pocket or inside tuner bores, you can tape them with some good masking tape.  Frog Tape purports to form a better-than-usual water-tight seal at the edge of the tape, but any decent masking tape will do fine as long as you burnish the edge to make sure it's not going to peel or allow seepage. 

 

[Rick]

I put tape over the holes, if they are the holes I'm thinking about.  Go easy on the liquid.

 

[Cowbell Fever!]

I am no finishing master, but how much water are you using?! I just use a tiny spray bottle with water and a tad of liquid soap. I wipe back often and don't bother plugging the holes.

 

[Tonar8352]

Wax works, but if I'm really concerned about a certain area, i.e. tuner holes,  I'll use mineral oil as a lube with a touch of medium rubbing compound and 800 grit wet/dry. It cuts fast and still polishes out nicely.

 

[Audiowonderland]

The trem post holes in particular, but all of them really. I don't want water getting into raw wood and messing up the finish

 

[alexreinhold]

Might be a stupid question, but why not dry sand?

 

[Cowbell Fever!]

Might be a stupid question, but why not dry sand?
[/quote

When sanding dry, the chance of buildup on the sandpaper gouging holes in the surface beyond the grit you are using is very high.

 

[Rick]

I dry sand and have no problems.  It's technique, and even with wet sanding you can't let things build up.

 

[Audiowonderland]

I dry sand and have no problems.  It's technique, and even with wet sanding you can't let things build up.

Perhaps so, but being relatively inexperienced in the finishing arts, wet sanding gives me a little more room for error

 

[alexreinhold]

I hate all sanding (single biggest source of error in finishing in my opinion). But I always dry feels more natural than wet.

 

[DuckBaloo]

There are lot of guides on when to use wet vs. dry.

• Dry sanding it uses more sandpaper because the lacquer waste "gunks" it up, significantly increases the risk of gouging the finish, and produce a less smooth final product
• Wet sanding keeps the lacquer from gripping the sandpaper, gives greater control on the process, and produces a smoother finish (even with the same grit)

Dry sand when you want to remove more material faster but aren't worried about the final finish, wet sand to remove less material and move toward a polished finish.

For the OP, I use mineral spirits instead of water. But plugging the holes saves some hassle.

 

[ValeBliz]

Why not wet sand using mineral spirits?

 

[bagman67]

Why not wet sand using mineral spirits?

1. Mineral spirits requires some ventilation, and is costlier by far than water. 
2. Some finishes will degrade with mineral spirits.
3. Habit, or preference for the feel of water vs. mineral spirits.

 

[Audiowonderland]

Well, I started finish sanding the test body.

Must be using too much.  I got some swelling in the neck pocket holes, Jack plate hole and the pickup carves. The neck pocket holes I can understand, The others not so much. Between the primer, sealer, white base and then black, those areas should have been sealed pretty dam well. The body was $30 ebay special so its not great wood and was carved for crap. I am wondering if that had anything to do with the issue.  My gut says if I was doing it right it would not have mattered. I fill holes with wax but how do I keep water out the pickup carve of a strat?

I did 800 / 1000 grit tonight. I will need to repeat that another night using much less water and get a feel for that.

To answer another posters question, I have a small spray bottle I use to wet the surface being sanded. I  thinking I will try using it to wet the paper instead

Any other advice?  May need to hit up Youtube again and pay closer attention...

 

[DuckBaloo]

I soak the sandpaper overnight. A few pieces that I can swap back and forth from. I've never applied the liquid directly to the guitar surface itself (but I know lots do).

 

[stratamania]

You wet the paper by putting it in a small bowl of water with a small amount of liquid soap and letting it soak. It lubricates the paper. You also need to regularly dry the body with shop towel or the like during the process.

From what you describe the body has had too much water directly applied to it.

Also be aware that in Warmoth's warranty about wet sanding is the following:

We'd like to offer a word of caution about wet sanding:

DON'T DO IT!

Only after there are several coats of hard finish on the body should you even consider wet sanding. Water will swell the wood and create all kinds of other problems. Be careful not to get water in the body holes and cavities. The end grain here is not well sealed and the glue lines will open very easily if they absorb water. We do not wet sand nor do we recommend this process.

https://warmoth.com/index.php/warranty/

 

[bagman67]

You also need to regularly dry the body with shop towel or the like during the process.

For maximum anal-retentiveness, change wiping rags when you change sandpaper grits, so you don't end up massaging coarser grit particles into your finer grit sanding.


Also, the point of the drying is so you can inspect to see whether you've leveled the entire area you're sanding.  On the first round, you're looking to make sure there are no shiny parts, and for subsequent rounds, you're making sure you've sanded the entire surface to the same sheen.

 

[stratamania]

You also need to regularly dry the body with shop towel or the like during the process.

For maximum anal-retentiveness, change wiping rags when you change sandpaper grits, so you don't end up massaging coarser grit particles into your finer grit sanding.


Also, the point of the drying is so you can inspect to see whether you've leveled the entire area you're sanding.  On the first round, you're looking to make sure there are no shiny parts, and for subsequent rounds, you're making sure you've sanded the entire surface to the same sheen.

Absolutely... :icon_thumright: