On flat grained wood the surface should be scuff sanded with 50 60 grit sandpaper.
How to sand and refinish cedar siding.
1 connect a pressure washer to a garden hose and pressure wash the siding to be sanded.
Cedar shingles can also grow moss and algae or develop iron staining which requires periodic cleaning.
This procedure will greatly increase the coatings performance but will not detract from a smooth finish.
The full strength solution should be strong enough to break down and remove failing coatings from the siding.
Use a 15 degree nozzle on.
Don t use polyurethane on rough cedar as the wood s coarse nature will prevent the sealer from bonding properly.
Mist it with water if the cleaner starts.
Stop to stir the stain every 10 to 15 minutes or the tannins will settle near the bottom of the 5 gallon bucket.
For smooth planed flat grained cedar some surface preparation may be desirable.
Keep the cleaner wet to ensure its effectiveness.
Surface preparation is not necessary for textured cedar.
Leave it on longer than 30 minutes if needed.
Let the cleaner sit on the cedar siding for 15 to 30 minutes.
Check the cleaner every 15 minutes.
Sand it to remove the loose surface particles.
Cedar siding though durable and able to maintain a good finish for a long period of time does sometimes get damaged and it is certainly not completely immune to rot no matter how well it has been treated and maintained.
Prep the cedar siding by cleaning it with a bleach and solution.
Refinish the rough cedar every year or two.
Cover cedar siding with primer to keep any tannic acid or natural red coloring from.
Department of agriculture s forest services laboratory recommends cleaning cedar shingles with an oxidizing bleach as opposed to a household bleach to avoid damaging the wood while you can use household bleach to kill mold and algae it tends to make the cedar shingle s surface.