View Full Version : Finishing Strip plank Jarrah and Pine

16th September 2016, 01:07 PM
http://d1r5wj36adg1sk.cloudfront.net/images/icons/icon1.png Finishing Strip plank Jarrah and Pine

I have just started prepping a jarrah and pine strip planked dirt boat deck,
Knocked all the glue and ridges off it and have sanded it down to 120 grit.

My question is; is 120 grit fine enough to now seal it? I don't require a piano finish but I don't want machine marks appearing after I have sealed it

I intend to seal coat with West 107/205, sand back, and then lay some glass ,add another coat of West rolled and tipped.

Then as many coats of a clear varnish to provide UV protection as needed.

Thanks for the help

17th September 2016, 07:07 PM
I went much finer than 120. The clear finish will highlight any scratches, swirls or other imperfections in your finish.
I used ROS with 60, 120, 180, 240, 320, than hand sand long the grain with 400.
This link may be useful
Sand Your Way to Beauty, Learn how to sand, sanding tips, Random Orbital Sander use, Sanding a Wood Boat, Sanding a Stripper, Sanding (http://www.laughingloon.com/sanding.html)
I also found Rob's tips on transparent glass layup on this site quite helpful.

17th September 2016, 07:09 PM
If going for a clear finish, the sanding marks from 120 will show through. 180 will show, but you really have to look hard, if you sanded with the grain. 220 grit is the lowest most will go on a clear finish and if sanded with the grain, no one will see the sanding marks. If you sand across the grain, 220 marks will be visible to a skilled eye. 280 is really fine and I wouldn't recommend any finer than this, though I know some (read really anal) that'll use 320 or 400, which is just too fine to get some coatings to stick to.

To seal the wood, apply the first epoxy coats (BoteCoat is my recommendation BTW, not West System) with a plastic bog applicator or putty knife, spreading out the goo on the surface, then mashing it into the surface with the blade. This forces the epoxy into the wood fibers. After letting it sit for a few minutes, the wood will have soaked up as much as it can and you scrape any pooling goo, onto other areas that still need it. Check out the "Epoxy Tips & Tricks" section on my site for a better description of this process.

The clear coats (polyurethane or varnish) should be at least 6 (or more) for serious durability. The varnish makers suggest 3, but this is just basic protection and you'll be touching this up every 9 months to a year, with the potential for UV damage, if you're lazy about it. In semi and tropical environments, you need a sacrificial coat each year (it literally burns away) and this needs to be over at least 10 mils (3 coats) of film thickness, for good UV protection. What's all this mean? Well the clear coat makers are right and 3 coats will offer protection (10 mils film thickness), but this is the bare minimum, so additional coats will get you more time and more protection. A show boat with a mirror like finish will have 15 - 20 coats. I know you're not looking for this, but consider the difference between the top of the line finish coating count and the basic recommendations from the finish formulators. If it was me, I'd put on 6 or 7, knowing I'll sand through a couple as I'm applying them.