Finish sanding with Rotex 125. Is it too aggressive?

[Gerry0611]

I used my RO 125 to finish sand a bar top made of oak.  The oak was originally milled as tongue and groove flooring.  After sanding through 80, 100 and 120 grit in the fine sanding mode, I felt I was done.  I began to apply a 1 lb cut of tinted shellac which immediately soaked into the oak and broadcasted lots of blotchy irregularities.  Some of the blotchiness ran 45 to 90 degrees against the flow of the wood grain lines.  I got to thinking that the RO 125 was actually too aggressive on the oak and tearing out wood fiber, thus encouraging the uneven result when coloring the wood.  Should I have gone to a higher number grit?  150?  More?
What about using a different sander such as a DTS?  One final question; does the oak automatically warrant treatment with a grain filler to achieve the uniform coloring I am looking for?

 

[WarnerConstCo.]

I sand in rotex mode to 150 and apply finish.  Works great for me. 

 

[wow]

I'm guessing that you stopped before you should have on your grit progression? I would have gone 150 then 180 and probably 220 or higher as well.

A 120 grit finish is good enough for a glue joint, but not for a finish. Of course, that's just my opinion...

 

[tjbnwi]

I'm guessing that you stopped before you should have on your grit progression? I would have gone 150 then 180 and probably 220 or higher as well.

A 120 grit finish is good enough for a glue joint, but not for a finish. Of course, that's just my opinion...

Depends on the wood.

Tom

 

[tjbnwi]

Do your prep sand in the rotary mode.

Luan mahogany plywood sanded to 150 in the rotary mode, stained then 2 coats of SW KA, no surfacer or grain filler.

Tom

 

[Stephen B]

[size=14pt]
I agree with WOW and Warner, you did not go high enough in grit. I usually go to at least 220 and sometimes to 320.

I use ROTEX mode generally only below 120, however there have  been some recent FOG threads suggesting ROTEX rather than eccentric mode be used with finishing grits.

The other thing to look for is your vac setting. Do not have it high, place your sander on the work with vac on manual ( ie sander will not operate) and turn down vac progressively until the sander does not appear to grab, then turn the vac down a bit more.

 

[WastedP]

The oak was originally milled as tongue and groove flooring.

Was this reclaimed wood?  Also, does the blotchiness that's perpendicular to the grain carry over from one piece of wood to the next?

I don't think I've ever sanded wood with the RO 125 with anything lower than 80, and usually just step up to 120, then 180 (I don't usually have 150 on hand).

Using rotary mode for fine finishing of wood sound counter-intuitive.  I've never used rotary over 120 on wood.  Maybe I'm missing out.

 

[rst]

Blotches can be caused by spots where the wood got wet and it will not always stain.  I worked as a stainer at a customer kitchen factory where we sprayed oak and maple with water before staining.  This raised the grain allowing the stain to penetrate deeply.  The parts were then sealer sprayed, sanded with 220, sprayed again, sanded with 320 and then finished sprayed.  The finish coat was sanded with 400 and oil, steel wooled, then Johnson floor wax was applied and buffed.  The finishes we lacquer based and really tough.  Of course this was in 1971 and finishes have evolved since then but I still use this same process with the water based finishes I use now.

 

[sae]

Blotches can be caused by spots where the wood got wet and it will not always stain.  I worked as a stainer at a customer kitchen factory where we sprayed oak and maple with water before staining.  This raised the grain allowing the stain to penetrate deeply.  The parts were then sealer sprayed, sanded with 220, sprayed again, sanded with 320 and then finished sprayed.  The finish coat was sanded with 400 and oil, steel wooled, then Johnson floor wax was applied and buffed.  The finishes we lacquer based and really tough.  Of course this was in 1971 and finishes have evolved since then but I still use this same  with the water based finishes I use now.

Hmm, great info.

What grit did you sand to before staining? I'm doing floors now, and I've read that no one sands to above 80-100 grit because any finer and you'd reduce the ability for the wood to take up the stain. Any truth to this?

 

[Scott B.]

I used my RO 125 to finish sand a bar top made of oak.  The oak was originally milled as tongue and groove flooring.  After sanding through 80, 100 and 120 grit in the fine sanding mode, I felt I was done.  I began to apply a 1 lb cut of tinted shellac which immediately soaked into the oak and broadcasted lots of blotchy irregularities.  Some of the blotchiness ran 45 to 90 degrees against the flow of the wood grain lines.  I got to thinking that the RO 125 was actually too aggressive on the oak and tearing out wood fiber, thus encouraging the uneven result when coloring the wood.  Should I have gone to a higher number grit?  150?  More?
What about using a different sander such as a DTS?  One final question; does the oak automatically warrant treatment with a grain filler to achieve the uniform coloring I am looking for?

Rotex is cleaner and more thorough. By cleaner, I mean no squiggly swirlies.