Cristal or Saphir for sanding painted porch deck?

[bassman00]

Looks like my big project this fall will be refinishing our front porch deck and stairs.  I will also be epoxying cracks as the refinish is sorely overdue. :-[  It appears that both of these papers would work for this job. 

Does anyone have any experience with either/both they can share?

TIA,
PaulD

 

[The Dude]

Bass, what flavor of wood is your deck?  Painted?  Treated?  Do tell us more,

Timmy C

 

[bassman00]

Bass, what flavor of wood is your deck?  Painted?  Treated?  Do tell us more,

It's painted.  Looks like 5/4 pine.  I don't know if it's treated but I doubt it.  The house is over 80 years old but I'm not sure how old the porch deck is. 

Thanks,
PaulD

 

[The Dude]

Bass, with the paint on there, you may want to tackle it first with the Cristal.  The openness of the scratch patten will hopefully keep the paper free from clogging for a while.  My thoughts are that if you go with Saphir on that pine, it may gouge it up pretty good.  If you are painting it again, why it may not matter too much.  You are probably OK with either...buy my .02 is to go with the path of least intrusion into the wood.

As always with woodworking, "there is more than one way to get to California from Nebraska."

Timmy C

 

[CharlesWilson]

The Cristal is less likely to clog on the paint, but will produce a more noticeable scratch pattern. The Saphir will easily cut through any protruding fasteners without undo wear to the abrasive, but as Timmy C said, it could also chew things up bit, and may clog.

Charles

 

[The Dude]

With Cristal being "fairly new" my mind didn't come to it immediately.  Charles is exactly right on the scratch pattern, however, my decision logic was that the scratch pattern won't be as deep as the Saphir.  I have never painted over a Cristal "thrashing."  I am interested to hear if anyone has gone back and painted over the "leftover" pattern from Cristal?  Hmmmmm  Very Interesting!

Timmy C

 

[Bob Marino]

There are no 100% right or wrong answers here, much is just personal preferance and trial and error, but  if the deck looks very rough, lots of old paint/junk on the surface, I  would start with the Saphir, maybe 80 grit - only because the backing is very thick and if your deck is uneven and rough, that backing can best stand up to that without tearing.
So, I would go 80 Saphir, 120 Cristal and depending on the scratches left, finish with Rubin 120 or 150.

Bob

 

[bassman00]

I will be using my Rotex 150 FEQ.  Probably should've mentioned that right off.  I guess I should wait on posting until my 3rd cup of coffee.    I have plenty of Rubin to smooth things out a little once the paint is removed and the deck leveled.  I will be painting it so I don't need complete perfection. 

The paint isn't that thick and has lifted/flaked off in many places.  It's not that rough though there are a lot of cracks and splits.  I plan on using System Three's Rotfix and Sculpwood to fix those.

I agree there's no 100% right or wrong.  Reading Festool's abrasives guide lead me to those two choices.  Just hoped that someone already did the trial and error.  I *think* I might have a sheet of Cristal that came with my RO150 so I will try it and see how it holds up.  I'll also see how long it lasts so I can have a better estimate of how much paper I'll need. 

Thanks,
PaulD

 

[Daviddubya]

I'll play the devil's advocate here.  I'd rent a stand-up oscillating floor sander for this job.  The kind I have in mind has a square pad that measures about 12" to 15" on a side.  No way would I want to be on my knees sanding a deck with any sander, not even a Festool, when I can stand and do the job better.  Use the Rotex for hard-to-reach spots.  All IMHO, of course.

When you are finished sanding try using Superdeck as a stain and sealer.  I have tried several deck stains/sealers, and Superdeck is the best I have found.  I use it on decks in near Flagstaff, at 7000' in altitude and harsh winters.  It holds up better than the alternetives.

 

[Dan Uhlir]

    Personally, I wouldn't be too concerned about sanding a porch floor, I would clean it more importantly, sand it to give it some tooth maybe straighten it out, what you reasonably can use some quality floor paint and coat it three times minimum. Use a mask or respirator too please. thanks dan

 

[munchcolo]

I don't have any input on which paper to use, but I do have some advice on the paint to use, if you haven't already decided on that aspect of the job.  Soon after we moved into our house 16 years ago, I sanded the wooden front porch and painted it with battleship grey oil-based polyurethane porch and floor paint.  It lasted many years, and I was very satisfied with the job.  Three years ago, I hired a painter to redo it, and he used water-based polyurethane porch and floor paint.  The water-based was not nearly as durable, and did not last as long, as the oil-based paint.  This summer, I sanded and repainted with the oil-based polyurethane porch and floor paint.  It is a MUCH better finish than the water-based.  I got it at Wal-Mart, but most BORG's and paint dealers have it also.  I added some "traction sand" (available at the same places) to the high traffic area by the front door, since the painted surface is pretty slick with a little snow or ice on it.

 

[Corwin]

Just used the little RTS 400 to sand down some nasty looking stuff the "builder" called window stop that they put around the glass panels in the railing around my decks.  Didn't have Saphir, but I did like the Crystal.  Used 100, I think, and didn't see the need to do any more.  Primed and painted, the railing now looks great -- better that it ever was new, unbelievable compared to how it looked after seven years of weather.  

The tops of the handrails were another situation.  Did those on a previous dry spell before the new Festools arrived.  Used my 150/3 with some Brilliant on that much smoother stuff -- and I found myself smiling away each time I touched the fresh surface as I sanded along.

Really, these sanders made quick work of fixing my railings.  Only real problem might be that all my neighbors have now seen some of my Festools in action.  Maybe I should have just done it all by hand.  

Corwin

 

[bassman00]

Thanks for all the replies and good suggestions.  I do have three dics of Cristal 60 and one of Saphir 36.  Definitely some aggressive stuff there.  I'll experiment with those before I decide which ones to purchase.  The porch isn't large so I can easily sand it through 2-3 grits in a few hours.  The fun part will be repairing the cracks and splits.  Hopefully, the System Three stuff works as advertised.

I do plan on using an oil based paint/solid color stain.  I used Flood Solid Color Stain for the back deck that's completely exposed and has held up very well for the past few years.  Unfortunately, I can't find it locally and the online place I bought it from before is either out of business or hiding from me.

Thanks,
PaulD

 

[bassman00]

Well, it's been a long time since I last posted.  Unfortunately, the weather didn't hold out enough for me to refinish last fall so it had to wait until this spring.  It is finished now. 

I wound up using both Saphir and Cristal.  Started with Cristal 60 and that worked pretty good on the areas where the paint was worn thin.  However, there were areas containing 6-8 coats of paint.  Thick coats.  Some of those layers were VERY tough (old lead paint, maybe?).  I tried Cristal 40 and even that wasn't cutting through all that well.  Stepped over to Saphir 36 and that worked for most of the tougher areas.  If my local dealer had Saphir 24 in stock, I would've tried that.  Because of this, it took a little longer than expected to remove the old paint. 

For comparison purposes, the Saphir 36 was very aggressive and took down the paint layers very quickly but clogged up often.  As was mentioned above, it handled some protruding fasteners without complaint.  The Cristal didn't clog much but wasn't as effective on the thicker areas.  It did a great job of eliminating the scratches from the Saphir.  I stopped at Cristal 60 as that was smooth enough for paint.

Next up will be refinishing some of the wood floors inside.  The Cristal will be used to take off the little bit of finish still there. 

PaulD