Keeping a Massaranduba deck looking good....

[HarveyWildes]

I have a 10 year old deck with Brazilian Redwood (Massaranduba) planks.  It's hard (Janka 3130), water and rot resistant due the gummy sap that dries in the wood after it is cut, so it is an ideal decking wood which I expect to last 30-50 years - probably longer than the treated joists underneath.  The deck is about 400-500 ft2.

Over time the wood surface yellows and then silvers.  We use the deck quite a bit, so it gets dirty as well.  However, the silver color is really just skin deep - just a little sanding gets down to the original color, which ranges from a deep orange to dark red.

About 5 years ago I power washed it and treated it with a deck preservative oil with UV protection against the Colorado sun.  Because of its resistance to water, some of the oil sat on the surface of the planks and hardened.  Over the last 5 years the wood has silvered a bit, and dirt has embedded in the surface, especially where the oil hardened on the surface.  So it was time to power wash again.  This time it was much more difficult.  In areas with the highest % of direct sun, the surface power washed relatively easily.  In areas that were more protected, the oiled surface did not power wash well at all.  I was power washing at 1500 psi.  Note that power washing itself gets back to the yellow color - you only get back to the original red if you power wash and oil, or if you sand.

Question 1:  Normally the recommended max psi for power washing decks is 1500 psi.  Higher pressures will start to erode the wood.  However, I'm not seeing any signs that the Massaranduba is eroding at 1500 psi.  Would it be safer to power wash this wood at pressures higher than 1500 psi?  If so, how much higher?

Question 2:  How should I treat the deck going forward?  I'm probably going to have to sand parts of the deck because my power washer maxes out at 1500 psi.  Once I've got the surface washed and sanded, should I:
  (a)  Just leave it alone so I don't have to power wash through oil the next time, or
  (b)  Apply oil, but remove any oil that doesn't sink into the wood, or
  (c)  Apply oil the way I did last time and just figure that cleaning and treating my deck is a beach?
  (d)  Apply oil the way I did last time and just figure on sanding the deck next time?

I'd appreciate advice on any solution that will take less work five years from now.

 

[crampedshop]

I, too have a Massaranduba deck. Mine is three years old and I haven't maintained it two years. It really needs a refresh. When I built it, I treated it on 4 sides with Penofin Marine Oil. Most of what I learned about treating the deck, I have learned from Scott Burt, of Topcoat Review. He is a regular contributor to the FOG. He has moved his info a site called IPEHELPdotCOM. I have been looking for another method of maintenance besides sanding and reapplying the Penofin. I have a pressure washer, but have been reluctant to use it on the deck. I recently came upon a process of thoroughly soaking and scrubbing using Oxyclean as a cleaner. The chemical in Oxyclean, Sodium Pecarbonate, is the main chemical in commercial deck cleaning products. Following the cleaning, I use Oxalic acid as a brightener. I have only tested the cleaning process on a small area and have achieved great results.

After I clean and brighten the deck, I think that I will use Ready Seal to treat the wood.

Pic of my cleaning test

 

[RKA]

I would go with option B only because it's a common process anytime you're applying an oil finish to wood.  But I have little experience with decks, so take that with a grain of salt or a sliver of pine.

 

[crampedshop]

Sorry, I never answered your question.

First, if you are only going to apply finish every 5 years, you will always deal with the situation that you have now. I have yet to hear of an oil finish lasting longer than two years.

If it were me, I would sand then apply finish. Whether you apply and then wipe off excess depends on the product instructions. The Penofin that I mentioned earlier wants to be wiped off after about 15 minutes. The Ready Seal does not need to be wiped off.

You never mentioned what you used for product

 

[kevinculle]

I have two ipe decks, the first one is on its third season.  We have power washed and oiled with Ipe Oil each year after the first when we oiled only.  As I power washed it this spring I started out holding the nozzle far enough above the wood to nearly cover the width of a nominal 6" board. As the cleaning progressed (deck is about 750 ft2) it became clear that that was not getting the weathered layer completely off.  I then gradually went to a pattern of holding the tip close enough to cover maybe 1/3 of the board and making overlapping passes.  This is with the white (widest fan) nozzle on my 2500psi washer.  My conclusion was that I could not harm the underlying wood with that nozzle and the wood I cleaned with this process showed much more vibrant color and grain while the earlier stuff looks dull and uniform in color.  Had I used this nozzle this close on pressure treated SYP or cedar it would have left serious gouges in the surface.  I made myself some notes for next year so hopefully the whole deck looks good!.

 

[Steve1]

My experience is pretty much the same as CrampedShop.  I have Ipe deck structure with Tigerwood deck planks.

I don't think you are going to get 5 years out of a finish.  I do mine every year. 

However, I would not suggest sanding it.  First try the proper cleaner -- the stuff is amazing.  The photo CrampedShop posted is typical results.  Penofin and Messmers are the common finishes.  I like the tinted Messmers - the added pigments give better UV protection, but not much difference between the two.  Instructions on both say to remove any oil that has not soaked in after half hour.  Leaving oil on deck just has it holding dust/pollen.    Both sell cleaners that are basically Sodium Percarbonate (same as Oxyclean).  But buying it from Messmers or Penofin gives you proper instructions on  concentration to mix it and instructions for deck cleaning.    I find the "Brightener" does not really brighten anything, but is also restores the Ph after cleaning, so should be used as directed.

Like CrampedShop, I am worried about using pressure washer on my deck, and don't do it.

Warning #1 is that the manufacturer's videos you see on You-tube of a guy cleaning his deck by moving a broom back and forth are not accurate.  You need to SCRUB HARD.  I find the only way to get good results is to get down on my hands and knees and scrub with a brush. 

Warning #2 is that these finishes have a viscosity of about zero.  Very hard to avoid splashing.  If you have a walkway nearby, cover it, and if you are doing railing against the house, mask off your siding in those areas. 

 

[lambeater]

Was in the same boat with my Cumaru deck. I did wash first with a penofin deck wash before finishing.

Lambeater
http://festoolownersgroup.com/home-.../refinishing-cumaru-deck/msg471702/#msg471702

 

[JSlovic]

I had a Purpleheart deck that had oxidized to a nice reddish brown.
I finished it with 2 coats after of Messemer's it got to the color I wanted and then recoated it every spring.
For recoating, I'd clean it with Messemer's cleaner and then roll on a coat of finish, brush it in really well and then wipe off the excess.
Beware these rags would start to smoke if I left them in a pile for 5 mins.
 
This process kept the deck always looking good.

From what I gather about your deck, I'd bite the bullet and sand the oxidation off and refinish it.

 

[HarveyWildes]

So I've decided to take off the hardest to remove stuff with a sander.  Here is my sander experience so far.  Read on for a Festool sander question .

I started with a Makita 1/2 sheet sander with 50 grit Rubin paper.  It clogged up almost immediately.  If I cleaned the paper, it continued to clogvery quickly, to the point of being useless.  I assume that clogging is some combination of the finish on the deck, the fact that the wood has a dried gum in the pores, and the Rubin sandpaper which seems to do best on unfinished wood.  I assume Granat would perform better.  But I don't think my local suppliers stock Festool 1/2 sheet paper, and I need it relatively quickly.

Next I tried my DeWalt belt sander with 50 grit Norton belts.  It did a great job until the platen heated up and the belts started to fail.  Once it heated up, the belts were failing consistently within 3-5 minutes.  Looks like this sander has a reputation for that.

Next I used my ETS EC 150/3 with a Granat 40 grit disk (I only had one).  It took a little longer than the other two, but just kept on trucking with none of the disadvantages.  It didn't clog, and the sander performed as expected, without heating up.

Given that the ETS EC 150/3 is my go-to finish sander for woodworking, I'm a bit surprised that it did as well as it did.  Given that the 3mm stroke is designed for finer work to begin with, I'm assuming that the 150 Rotex would outperform both the Makita half-sheet and the DeWalt belt sander, even if they were working as expected (which they are not).  Am I missing something???

At any rate, I'm tempted to pull the plug on a Rotex and a box of 40 grit Granat to finish the job.

Comments?

 

[crampedshop]

40 grit might be too rough to apply finish. I use 80 grit Granat when prepping my deck. You might have to run 60 and then 80 before applying finish.

 

[WarnerConstCo.]

Oxicilic acid scrub and use a twp 100 series.

The oils suck.

 

[Cheese]

At any rate, I'm tempted to pull the plug on a Rotex and a box of 40 grit Granat to finish the job.

Comments?

I'd definitely pull the pin on the Rotex,  [big grin]  however, I'd start with 80, then try 60 and only go to 40 if the other ones don't work.

 

[nickao]

At any rate, I'm tempted to pull the plug on a Rotex and a box of 40 grit Granat to finish the job.

Comments?

I'd definitely pull the pin on the Rotex,  [big grin]  however, I'd start with 80, then try 60 and only go to 40 if the other ones don't work.

It's Massarnduba with  dirt embedded. Don't waste your time with anything other than 36 grit to start, 40  the highest.  I am sanding some today actually. Though Ipe is a bit harder, Massaranduba is more a problematic sanding. And wear mask unless you want to  go in the hospital. IMHO there is no wood on earth that creates as toxic a dust as Massurnduba. The guys laid 4000Sq ft in my old home and I warned the workers, they didn't listen to me. After two hours they had to go home and didn't come back for 3 days and with respirators. And all they were doing was cutting the flooring edges to lay it down, sanding  is far worse. USe a dust collector even if you are outside.

I bought a box of 36grit Saphir that came in yesterday just for the Massrundba sand I need do today.

 

[leakyroof]

Oxicilic acid scrub and use a twp 100 series.

The oils suck.

  Didn't you use to use the Messmers on your IPE decks that you built?

 

[nickao]

I want to say what I said in the other thread.

I never ever sand decks to clean them as the first step, sometimes I find they dont need sanding at all. Always use a deck cleaner and rejuvenator made for your particular wood two or threes times first.

 

[HarveyWildes]

I want to say what I said in the other thread.

I never ever sand decks to clean them as the first step, sometimes I find they dont need sanding at all. Always use a deck cleaner and rejuvenator made for your particular wood two or threes times first.

I've ended up using the power washing approach first, with generic deck cleaner since I couldn't find anything that was specifically made for Massaranduba.  I have ended up sanding small parts of it with a Rotex and 40 grit paper, which only makes marks like 40 grit paper for about a minute, and then it's smooth enough to pass.  It's marginally noticeable, but not too bad.

 

[WarnerConstCo.]

Oxicilic acid scrub and use a twp 100 series.

The oils suck.

  Didn't you use to use the Messmers on your IPE decks that you built?

I did, but soon realized that it sucked long term.

It goes against everything said to build a film finish on these woods, but it works great, easy to clean and maintain.