Starboard marine lumber - how to finish cut edges?

LaRea

Can anybody suggest a good way to finish cut edges on a piece of Starboard marine lumber?

I try to avoid having visible edges, but that's not always possible.  What I usually do is round the edge with a router, and sand it smooth.  But the rest of the board has a pebble finish, so the sanded edge looks different.  No matter how smooth I sand it, it's never quite right.  I want a way to reproduce that pebble finish on the cut edges.  

Maybe some sort of hand-held knurling tool with a diamond pattern ... anybody ever tried it?

aero3113

I think plastic welding kits come with different patterns that you can melt into the surface.

TonyG13

If I can find a link to the video, I will update this post.

I had the same issue and I saw a video the other day (link was either on this forum or somewhere else during my search) in which the guy heated up the seaboard surface with a propane plumbers torch to just barely the melting point, then quickly dabbed the surface with sandpaper -- the grit matching the type of pebble effect he wanted to mimic -- and the sandpaper was in effect his patterning tool. The key was to dab, not pull or scrape. The dabbing created the nice pebble pattern. Just need to find a grit closest to the surface you have.

Looked good in the video, I just haven't had time try it.

You may want to experiment on a scrap first! LOL

TonyG13

Found the video:

https://www.youtube.com/watch?time_continue=3&v=n8MdVNAGSE8

The pertinent section (using the sandpaper to pebble the plastic) starts around the 4:30 mark. He's doing it on thinner piece of HDPE, repairing a jet boat, but Seaboard is also HDPE, so I think the same technique would work.  

diggin2day1

That’s a tough one!

LaRea

Interesting.  I think it would work.  Definitely need to practice first!  That stuff isn't cheap.

LaRea

TonyG13 said:

Found the video:

https://www.youtube.com/watch?time_continue=3&v=n8MdVNAGSE8

The pertinent section (using the sandpaper to pebble the plastic) starts around the 4:30 mark. He's doing it on thinner piece of HDPE, repairing a jet boat, but Seaboard is also HDPE, so I think the same technique would work.  

@TonyG13 thanks!  I tried this method, and it works fine on Starboard. 

I used a router to make a 1/4" radius corner, then sanded it with 100-grit paper on an orbital sander.  Then I briefly heated the surface with a torch, and dabbed it with clean 100-grit sandpaper to produce a pebble finish. 

What I got is a nice matte finish that hides the toolmarks and basically just disappears.  If you get up close and look for imperfections, yeah ... it's not a 100% perfect match.  But if you see it from typical distances, nobody's going to notice.  And it looks way better than tool marks or a sanded finish.  

One thing to note:  the heat can make the original finish get slightly shiny, so you have to be careful with the torch.  

TonyG13

@LaRea - Glad it worked out! Any pics you care to share?

LaRea

I'll post one when I finish the install.  Nothing special ... just a mount for a cockpit TV.  

LaRea

Here's a shot of the finished project, taken from a closer distance than most people will ever get.  To be honest, I could have gone back over it to get a more consistent finish.  But its job was to disappear, and it does that nicely.

Actually, it's hard to get a photo that really shows the finish.  The second photo doesn't quite capture it.

TonyG13

@LaRea - Good job!

Seabutt

You can finish a saw cut edge with a flush cut router bit. I do it all the time on industrial Plastic fabrications and marine applications.It gives it a machine looking smooth edge. Then you use your radius router bit. 

LaRea

@Seabutt good point.  I was looking for a pebble finish, but a router bit would give a nice smooth finish.

Seabutt

LaRea, yeah i liked your idea about the using the sand paper as a template and heating up the edge. Actually will be trying it on the next project.