Tips on sanding lams?

[mmattockx]

So, I built a thickness sander. Seems to work well so far and I have been hacking away making bend test pieces and sleds and so on. But I am finding (as with most things in woodworking) that getting a lam to the finished thickness I want with the surface finish I want is trickier than I expected. Is there a thread with tips on how to get the best results sanding lams and tricks to use, etc.?

So far I have found that running the lam through the same setting several times when near the finished dimension is best for consistency and a smoother finish and that I need to sand both sides of the lam to get a consistent thickness full length, even if one side has a nice clean saw cut on it to start with. I am using 60 grit paper and that seems fine enough for good gluing surfaces if I take some care and run the multiple passes near the finished dimensions.


Thanks,
Mark

[Shredd]

not exactly sure what you want...  for the most part it is pretty cut and dry...  sounds like you got it going on...

  here are some of my tips...

 when you are taking off barely any stock at all or running it through the sander twice without changing up the settings...  the term for that is called 'sneaking up on it'...

   i like to use 60 grit alum. oxide or 80 grit zirc...   

    make sure your lams don't slip on the sled...  if they do, for a rig like yours try some starboard for the surface that your sled slides on...   you will have to change it out now and then because it will wear...

   when you are done with your lams through the machine and if they are fuzzy i like to line two of them up side by side and go over them with a sixty grit sanding block with fresh paper...

[kennym]

Definitely sand both sides. 

An even feed rate if you don't have a conveyor feed will make them more even too.

Last couple passes I don't change sander, just flip lam(s) over so both sides end up the same.

My sander will take off .002"  without changing sander, then .001 more if I run thru again.

You don't want a super smooth finish, so the glue can get a good grip on the lam.

60 grit is what I use, tried 40 but left grooves that would show on darker lams and clear glass.

[Mad Max]

with EA-40 (smooth-on) epoxy you can use 120 grit.
I use 80 grit

[Roy from Pa]

What Kenny said.

[Crooked Stic]

Side to side adjustment needs to be dead on. Still flip the lams.
constant feed rate.
and neak up on it at last. Kenny knows his machine yours may be different.

[kennym]

Mike is right . Get machine as close as you can to perfect , then sand and flip .

[mmattockx]

Thanks for the replies. So far it seems I am doing OK with my stuff then. Side to side on mine is very good, less than 0.001" difference on 2" wide lams. I can't measure any better with calipers on wood pieces ground with 60 grit.

Another question that is related to this. How do you guys grind the tapered lams? Full length taper, leave a section of parallel at the end that goes into the riser or something else? I am thinking about how to set stack height and the easiest way to hit my target there.


Mark

[Crooked Stic]

Full tapers. And I measure the butt for the stack.

[kennym]

Most folks measure the butt thickness, a few guys measure at the fades.  You could  do the butt thickness taper , then run the taper thru to parallel the thick end for a ways I guess if need be.

[jess stuart]

I am kind of weird.  I measure the butt, mid limb, and tip thickness on my lams.  I pay the most attention to the mid limb thickness as the butt will usually have some snipe giving you a reading a few thousandths less than a couple of inches down the lam.  Seems I come out much closer on weight doing it this way.

[Crooked Stic]

Nothing weird about that. I grind in pairs and always compare the thin end to each other.