Obsessed with trying to get a flawless sand job!

General Discussion
1

I am sanding my 8 th board I’ve done. Everything is coming together. I feel that I am getting good laminations and pretty good hot coats. Been using RR kk. Wanted to shape eps, since I loved riding eps boards and poly stunk out my house when I worked in the garage. Wife wanted to kill me. I had to switch to epoxy.  I am from long island so i have been dealing with cooler temps in the past few months. Heating the resin definately lets it flow better.  Helps with wetting laps and flowing hot coats.  I dont feel my glassing is lumpy at all,( now, first two were a bit rough) but when i start sanding with 120 i cant seem to get all of the shinies as i progress through my grits. I am using a variable speed sander 600-3000 11 amp wen sander / polisher. Seems to bog down a bit with moderate pressure. Using a medium flex pad and a soft yellow pad. While reading through the archives today something clicked and I tried it and worked. I used the medium pad with 80 grit at about 1500 rpms. I didn’t rush to try to emulate the JC sander guy… I went slow and was careful. I flattened everything out pretty good, followed with the 120 … And there you go… I only had to hand sand out a few shinies to  progress with a really quick pass of 220. I usually start rails at 220 so it was perfect. 

 Can Any experienced sanders out there critique my new work flow or am I on the right track. I used about 2000 rpms with the 120 and prob back down to 1500 with the higher grits

2

I’m having similar issues. I plan to take extra time when finishing my blank on the next one. My theory is that a flatter blank will prevent the sandpaper skipping over spots when sanding.

3

You're both right.

4

Dude - there is a whole thread on sanding, complete with drama and pages of good info, around here somewhere!

5

I just shaped another board , first with side lights … And it is the flattest smoothest deck yet.  Glass this week sometime. I’ll let you know!

 

I was trying to find a good sanding thread. Found a few, I’ll search harder for the one your talking about

6

I think this is the thread that Huck is talking about: http://www2.swaylocks.com/forums/advanced-sanding

Cheers
Paul

7

It sounds like you are going through the progression of learning what works for you. It’s been said before but with sanding, the better you do the previous steps (shaping, laminating, hot-coating), the easier your sanding job will be.

I’m pretty early in the process (but a few dozen boards ahead of you). One thing I found that really helped was to brush on a “cheater coat” of kwik kick around the laps. When it cures, you can be more aggressive sanding the laps flat without worrying about digging into the foam. Not my idea, I learned it on here. An ounce and a half of mixed material should be enough to get around the laps on a 6-8 foot board. Flat laps lead to less exposed weave and shinys when sanding your hot coat. The lap area was always a trouble spot for me, until I started with the cheater coat. More advanced guys probably skip this step. Maybe I’ll skip it in another hundred boards.

Another thing to improve your sand job: I try to do a thorough job with 100 grit on the entire board. I do most of the board with the yellow soft power pad. I also got a super soft ferro pad where I lightly touch the rails. Pulsing the trigger here with a very light touch. Then I finish the rails by hand (with 100). If you start the rails with 220 that’s got to be alot of wasted elbow grease.

Once I’ve done the entire board with 100, I can assess where the trouble spots are: weave, shinys, pin-holes. Then I mix up another small batch of KK (1 oz resin, .5 oz hardener and a few drops of Add F) and spot fill the trouble spots with a 1" chip brush: dab the holes and brush out the weave/shinies.

Once the filled trouble spots cure, then I move up to 150 grit. For me, 150 is the transitional grit that is coarse enough to smooth out the spot-work but not so coarse to do damage. Still the same strategy as the 100 grit: yellow PP on the flats, soft ferro and hand-sand on the rails.

Once the 150 is done, the trouble spots should be gone and you should have a pretty good surface. At this point, I put 220 on the ferro and do the whole board. With 220 you are removing little material and just smoothing out the 150 scratch marks. Also finish hand sanding the whole board with 220.

After 220, then repeat with 320, same process. And it’s done.

Anyway, that’s what works for me with Kwick Kick.

 

8

Oh, and by the way, I’m not a fan of the KK at all.

I like the regular CE / fast.

I’ve only built like 5 or 6 so far so it could be due to inexperience tho.

9

Right on McDing.

Lookin’ forward to the next one for sure.

10

Yah, let us know for sure. Side lights huh? Whoda thunk?

I need to get some of those

11

I feel the same way about the kk. I feel I got better flow from the CE resin. Kk feels thicker for some reason. Gets frothy faster. I don’t know. Could just be me. 

12

Thanks for the detailed response Jaime … Vey much appreciated. Gonna combine some of those tips into my routine and I know it’s gonna yield great results. I get caught up sometimes in havi g to go back to fix things , so I naturally wanna get it right the first time around. Time is tough to come by lately to get in the garage and work on my boards, but the extra step will only set me off a day and then I’ll have great end results!  Thanks for taking time out for the posts and everyone else who chimed in

13

I’ll try to chime in with a tip or two for epoxy.  The nice thing with epoxy is that you can sand the lam coat pretty easily compared to poly which requires different steps.  So aside from the obvious smooth finish on the foam and tight lamination there are a few tricks.  

If there is a super high spot like a booger under the lamination or a high spot from a cloth fold I don’t even hesitate to take a 60 grit hard pad and just take it right down.  There is no way your going to hide something like that with basting.  Better to just deal with it first and cover it later than the other way around.  

So lam bottom take down lap as low and flat as possible with a 60 grit disk on an air angle grinder.  Lam bottom and take down any really high spots with the 60 grit again.  

Now its all about how much time and material you want to use.  If your deck laps look high then its optional to baste the deck at the lap.  If you go double 6 on th deck it will usually be ok as it covers any high/low spots.  For sure baste the bottom lap.  For basting just for clarification I try to get as much material from the flat up to the lap, kind of like a ramp with some going over the actual lap.  

Then if I want to get a super smooth finish I’ll take a 6" hard disk with 60 grit and flatten the basted areas.  A sander gave me the best tip that your actually not grinding as much as your cutting the baste.  The heavier grit allows you to cut and the hard disk allows it to stay flat.  So light pressure and a steady hand.  Shave those high spots flat.

Then wipe with DNA and sand coat the whole thing.  The other thing with epoxy is that I try to sand the sand coat as soon as it is sandable.  I’ve heard people call it green.  It’s hard for sure but definately not cured.  It is like night and day.  Once its fully cured its way harder to sand.  So once its good to go I’ll hit the flats with 100 grit on a medium pad then progress to 220.  Rails get a soft pad and hand sanding.  Once its at 220 I’ll either start wetsanding up to 600 or give it a sealer coat of acrylic.

The missing ingredients here are paper quality and tools.  You’ve got to use fresh quality paper especially with epoxy and a good sander/polisher.  I have a 2500 rpm dewalt that I trigger for the flats and a 1750 milwaukee for the rails and polishing.  Also as I’m sanding I try to keep the paper clean.  Every so often I’ll stop and blow the paper off.  If you keep sanding with powdered up paper it just heats up the material and makes for shiney swirls.  Not nearly as bad with the lower grits but for sure with the higher ones  

There are other ways to skin the cat for sure, but this is just my way.  Another thing is epoxy is the worst for sanding, such a pain in the ass.  UV poly is the bomb!