Lap sanding tool

I realize the standards are sanding block for garage guys and angle die grinder for the pros, but how bout one of those oscillating multi-tools?

 

I only ask because I already own it.

My oscillating tool,  which is not a qualty one, is poor at sanding anything, much less gummy laminating PE resin, I Mainly use it with saw blade for plunge cutting, sometimes with flat knife blade for scraping.

if you can find oneof these at an autobody site

https://www.wonkeedonkeetools.co.uk/files/what-is-a-vixen-file

cut thru anything

easy to clean with acetone and a soft wire brush

 

If you have an air compressor;  You can buy one of the best Die Grinders ever made for $15 at Harbor Freight.  Makes quick work of laps, cut or freelap.

Like McDind said…plus the 80 grit snap lock discs and soak them in acetone bucket and spin them clean when done. Also, I never oil the grinder to make sure it does not  blow and contaminate the lam. They are $15 and have lasted 100’s of boards.

I use both a die grinder and vixen, but my go-to is the vixen.   Pros: it’s less prone to gouging, better at keeping things flat, and less dust.  Cons slower and more elbow grease needed.

There’s the common file length ones, but I recently found these small palm size ones and they’re simply awesome - especially when cleaning up around the nose and tail.

https://www.yardstore.com/vixen-file-on-palm-block

I like to use a right angle drill with the rolox attachment for laps. I have 3 sizes for the rolox disks from 1’" to 3" in various grits, but the really rough grits are great for sanding laps. I like to use a disc that is wider than the shaft that holds it. I often hold the drill in one hand and a vacuum in the other, or I’ll sand a little then vac up the glass dust.

I also use Vixen files, but I tend to use them more once the whole board is laminated. I don’t have an oscillating tool, so I don’t know if they would be better or worse.

https://www.harborfreight.com/power-tools/drills-drivers/right-angle-drills.html

https://www.harborfreight.com/3-in-surface-conditioning-kit-19-pc-60752.html

I’ll get a pic up of the die grinder I use, but it is one of the smallest made and has no trigger lock.  No lock makes it very convenient to use.  Harbor Freight sells a packet with a backing pad and a few Rolock “type” disk.  I buy my disk online most of the time, but want to buy Indasa the next time I get low on disks.  Letting the resin soak off in a pale of acetone makes a box of fifty last a long time.  I use 50 grit.  It’s aggressive enough and doesn’t gum up as fast as finer grits.  Wanted to buy 80 this last time, but couldn’t find them.

These are my go to lap grinders;  $17.88 in the most recent Harbor Freight catalog.  You’ll never buy anything better even if you pay 5X the price.   2" and 3".  I have used 2" for years, then one day I noticed that Dave Gott was using a 3".  In my opinion, it is probably easier to keep the 3" flat when grinding laps.  Especially multiple relief cuts at the nose and tail.  I buy the disk online.  Those 2" have been used and re-used too many times to think about.  Like Diamond, I don’t oil them.  I still get years of use out of them.  100’s of boards.  If you do put 4 or 5 drops of oil in , put the drops in the air coupling.  That’s the standard way of lubing any air tool.  No WD or anything like that anywhere on the outside.  I bought them on sale for as little as $9 and $12.  I try to buy an extra now and then to keep in reserve.  My fear is they will stop making them someday.  No trigger lock makes them easier to use.  Only die grinder I have ever seen manufactured without one.  If you’re building surfboards and don’t own one, you wouldn’t take good advice if it bit you in the a$$.

what size compressor do you need for those grinders?

And actually what size compressor’s are most shapers using?

Hobby builder and here’s my specs.  It’s a husky brand, 30 gallon,  1.6 hp, 120v, 6.2 sfc @ 40 psi,  5.3 sfc @ 90 psi.  

 

I also buy cheapo grinders, don’t oil them, and just replace as needed (I oil my other air tools, just not those used for board building).   I even cringe a bit when blowing the board off with just the compressor -  only do it as necessary, from a distance, as short as possible.  I have a healthy fear for oil contamination when building.  My own hands, tools, compressor, etc.  

I have a couple of 20’s.  Sometimes I have to wait for it to catch up, but it’s not crucial like it would be if I were painting.  A small “pancake” contractor compressor will do it.  It just turns at slower RPM’s and has to catch up.  .  I just had one of these die grinders literally “die”.  10 years old.  Went to Harbor Freight and bought two more.  Maybe Harbor Freight sells online.   If not maybe someone can get you one over here on da mainland and send it to you.  Lowel

1st tip is to do a mini-hot coat around the perimeter where you are going to sand.  That’ll reainforce the foam just enough so you won’t dig into it if you make a bonehead mistake.  It also allows you to take down the glass shards to nothing - to make a good surface for the next layer of glass.

2nd tip is to use a random orbit sander.  I use a random orbit sander kit for my angle grinders.  That way you eliminate the high tip velocities that all circular sanders have - and that is what causes all the mistakes.

3rd tip is to do a uni-bond glass job.  I haven’t done this in decades, but the trick is to flip the board over and glass the deck before the bottom has cured.  That way both layers are actually one.  It takes LOTS of planning and LOTS of finess.