Sanding Epoxy

I completed gluing my puzzle joints on my Shearwater 17. It has cured for about 60 hours and looks pretty good. There are a few small areas that could have used a bit more epoxy on the glass strip but the joints are well covered. I had some epoy leak underneath the joints leaving a film and some epoxy slag on the outside panels of the boat. Do I need to sand that off using a scraper or sandpaper now or wait until I get thge boat togeather for more support. I don't want to break a panel or damage it being to agressive. Thanks !

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RE: Sanding Epoxy

I would use a cabinet scraper to clean up the glue. You will be able to control the scraper much better than a sanding block and not have to worry about removing too much wood on the surrounding areas.

RE: Sanding Epoxy

Thanks, I will give that a try tomorrow. If I would have taped the other side off before gluing perhaps I could have avoided the extra work but you learn as you go.

RE: Sanding Epoxy

Scrapers are good tools in the hands of people who know what they're doing, but sanding blocks work easily and well for a job like this.  I think the simplest solution is to make sure the work is lying flat and is well supported, and then sand with a medium grit paper on a decent quality sanding block, sanding with the grain of the wood.  Be sure to keep the block flat, but that's easy to do.

You could also use a small random orbital sander or palm sheet sander, too.  Just make sure you keep it flat so the edge doesn't dig into the wood.

I've used both a sanding block and a random orbital sander to deal with very similar problems, and it's worked well.

In any case, get rid of the excess while you can still lay the wood flat; it's much easier than trying to do it after the boat is partially assembled.

    -- Jim C

RE: Sanding Epoxy

Thank you Jim, I just got through sanding a joint to see how it would turn out. Works great but takes a lot of slow careful work. I know what I will be doing this weekend. I made the error of using a cheap plastic under my joints when I glued them. The result was when the epoxy seeped through the puzzle joints it took on the form of the wrinkeled plastic beneath. Looks similiar to a choppy body of water made of epoxy. I'll stick with the sanding and chalk it up as a lesson learned the hard way. Mark

RE: Sanding Epoxy

Sanding, I think the main thing you need to be a little careful of is to take care not to oversand at that point. It's an ugly brown mark on the panel if you go through the veneer anywhere, and the veneer is not real thick. So err on the side of leaving a little excess epoxy, rather than cutting too much into the wood. I cleaned my panels up with a sanding block before assembly but, to me, it seems a little easier and safer to leave the final smoothing on the joints until after the hull is all glued up, when you do the finish sanding in preparation for glassing. The puzzle joints (at least the ones on the hull) will be presenting a slightly convex surface at that point so it is slightly easier to knock down high spots in the epoxy then. 

--

Ogata (eric) 

RE: Sanding Epoxy

Oh yeah, am I the only one not able to get to any of the "Tips for Boatbuilders" today? Firefox 3 on both Mac and linux just gets a white frame where the article should be. Safari on Mac does the same. There is an article there titled, "Don't Oversand" but I have no idea what it says anymore.

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Ogata (eric) 

RE: Sanding Epoxy

I'm getting the same thing on my Mac/Safari.... 

RE: Sanding Epoxy

Eric, I am gald you posted your note. I sanded my hull panels first and may have gone a hair too far but I plan to paint the hull so I should be ok. Now I know to take it easy on the rest of the boat. I look at all these building errors I make as experinece toward building my next boat.

RE: Sanding Epoxy

Re Jim C's comment:

"Scrapers are good tools in the hands of people who know what they're doing,..."

my opinion is different.  I am not a skilled woodworker but for me, the cabinet scraper is  simpler to use.  Someone posted a photo (above), which shows why.

The scraper "automatically" just shaves a curl of epoxy off the high spots, without cutting the surrounding wood.  For me, that would be impossible to do with a sanding block, because it requires to maintain the block perfectly parallel to the wood surface as it rides over the bumps and ridges.

I guess it's also because with a scraper, you can feel, see, and hear when you're on flat wood.  When you hit a bump or ridge, you feel it, and you can see where it is as the white shaving starts to curl up.  I suppose that without thinking about it, you learn to take a light pass to find the bumps or ridges, and then you go back to shave off those high spots.  With a sanding block, you don't get much of this feedback.

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