How fine is too fine

skeaterbait · December 14, 2017, 08:46:00 PM

So it hit me today as I was making another failed attempt to make lams (sled issues this time), is 180 grit too fine for a good gluing surface. It doesn't sound all that fine but it sure does feel smooth.

Robertfishes · December 14, 2017, 08:59:00 PM

pretty sure most guys grind lams between 40 grit and up to 80 grit.

kennym · December 14, 2017, 09:28:00 PM

Yep I like 50 for most lams, too coarse and you can see the sanding marks but want rough enough to get the glue a good bite .

December 14, 2017, 10:28:00 PM

I like 60...

fujimo · December 14, 2017, 10:31:00 PM

i have used 120 in the past, cos thats all i had- but will go to a 60 in the future.
the 120 worked fine- never had a delamination...... yet

bamboo · December 16, 2017, 07:04:00 AM

QuoteOriginally posted by fujimo:
i have used 120 in the past, cos thats all i had- but will go to a 60 in the future.
the 120 worked fine- never had a delamination...... yet

120g is what smooth-on recommends-

-i use 60g

Roy from Pa · December 16, 2017, 07:08:00 AM

I've always used 60 grit with no problems. Then it already has a rough enough surface and I don't need to toothing plane it for a better gluing surface.

Mike Mecredy · December 16, 2017, 04:02:00 PM

I wouldn't use any thing finer than 60 grit, I myself, usually use 40 grit on my drum sander.

Crooked Stic · December 16, 2017, 04:24:00 PM

I think most of the glass you get the glue side is 80 grit. Seems to do just fine. Smooth on does say 120 so I think 120 to 60 60 myself.

Bowjunkie · December 16, 2017, 05:30:00 PM

40 or 50 for me

monterey · December 16, 2017, 07:16:00 PM

Whatever Super Grit "coarse" is. :confused:

I don't grind very many. Results are not up to snuff yet.

skeaterbait · December 16, 2017, 09:36:00 PM

Thanks all. I have some 60 and 80 grit on it's way. Until then I guess I will just have to look at all this birdseye and curly maple and think about it.

I am still sitting on some amazing bocote I got from KennyM but I want to get more experience under my belt before attacking that.

mikkekeswick · December 17, 2017, 02:52:00 AM

To be honest you could probably get away with any grit.
Modern epoxies are superb at 'wetting' the surfaces and have no need for 'roughed up' surfaces. Check out a 'smooth' piece of wood under a microscope....!
I use 60grit as sharp 60 will remove material quickly without burning issues.

BigJim · December 22, 2017, 02:33:00 PM

60 grit for me on everything unless it needs to be stained or dyed. Maple is a little different in that it shows just about every little sanding line. I use 80 on that.
120 if it gets dyed. The dying itself will open the pores a bit though and help it absorb more I suppose. It may not matter, but it has been working.

BigJim

skeaterbait · December 23, 2017, 07:52:00 AM

Thank you Jim, I have a fair bit of maple I am going to be working with to start and I will remember this.