Laguna 14BX fence not flat

[Jason Mako]

Hello,

Newbie woodworker here who recently got a 14BX and as I was squaring the fence to the table I noticed the fence isn't totally flat - it bows slightly in the middle. If I remove it and put a square or other straight edge on it, it rocks back and forth and when measured with a feeler gauge it's about .010" out. I went to the store today and tested another one and it's basically the same.

Does this even matter and I'm being picky over nothing?

Thanks,
Jason

[Al Weber]

In which dimension is it off? If in the long direction I suspect it is academic but if in the short upright dimension it could be an issue when trying to resew. Check with Laguna to see if it is within their limits and see what they say. They might replace it if it is still under warranty. I'll check my 1412 to see whether is is flat.

[Robert Hazelwood]

Mine was a little out as well, but probably less than 0.010. I didn't notice it until I tried to cut some tenons on wider stock, where the faces of the tenoned pieces needed to be perfectly flush with the faces of the mortised pieces. Fitting up those tenons revealed that the cheeks were not quite parallel to the faces of the stock. When I went to check that the fence was parallel to the blade I noticed that it was convex across its width.

Anyways, I never noticed it for two or three years into owning the saw, so in my case it wasn't the biggest deal. Mainly it would be a problem for taller cuts and resaws that need high precision and a high degree of parallel-ness with the face registered against the fence.

After I noticed it I had to do something about it, currently I've drilled a couple holes in the fence and bolted a plywood face on and shimmed that face until its dead flat. The downside to this is you can only use the fence in the tall configuration. It would be better to just lap it flat.

It's an aluminum extrusion, and most aluminum extrusions I've come across were not that flat. Mine and the two you've looked at were not. So chances of getting a perfect one from Laguna seem pretty low, though I suspect most of them are better than 0.010" out. It shouldn't take too long to lap on a surface plate.

[glenn bradley]

Extrusions are not true unless machined. The good news is that aluminum is relatively soft and easily shimmed. Depending on the support behind the extrusion a bit of foil tape or even painter's tape can true things up to within the tolerance you may need. My extrusion did not have perfectly perpendicular edges, no surprise, these things are heated, squeezed out like toothpaste, cooled and stretched. When I moved from the tall to the low fence position, things were off a bit. A little experimentation and a strip or two of 1/4" painter's tape and I was all set. I can now change back and forth without concern.

[Jason Mako]

@Al Weber, in the short, upright direction.

Thanks for the comments all.

I guess I'll either gum up some sandpaper with aluminum while lapping it flat or use Glenn's tape trick as I don't see how any shimming behind it would change dimensions.

[Jamie Buxton]

When I wanted to lap my extruded aluminum fence, I found that it was anodized. The anodized layer is thin, but it is very hard -- much harder than raw aluminum. It quickly dulled sandpaper. I eventually resorted to a belt sander and several 80-grit belts. However, when I got through the anodized layer, the belt sander gouged the soft raw aluminum. So then there was a long-ish lapping process to take out the gouges. Altogether it was a lot more work than I expected.

[rick berger]

Unbelievable! I just went to do some resawing, and realized mine had this belly as well! That led me to this thread.....
Mine is much worse... if I put a straight edge and make contact with the bottom two “ribs”, the highest rib is .043 gapped!
Need to resaw some hard maple, like now....not sure what to do aside from a sacrificial fence. Anyone find an alternative for purchase that is actually milled flat before anodizing?

[Alex Zeller]

If you don't use the fence in the low position I think I would attach 3/4" hardwood to the fence with some countersunk screws. From there, assuming you have one, a jointer can flatten the board. From there you may need to play with shimming if it's not perpendicular to the table. You'll give up a little depth but it would probably be the easiest solution.