hi, will be doing my first cut laps. i know what ill be doing (well what i should!). its just after you've cut the lap, do you sand it down like on free lapping? im confused becuase if you are using tints, doesnt sanding discolour the tint?(what i read). Im glassing clear, but just wondering.
thanks
I've only done cut laps w/tint on the few boards I've built and it's not difficult. I do find that I have to sand the lap where it's buckled and lightly along the cut line. It's not too bad and as long as I remove the sanding dust with the air compressor it all works out. However, I am not a professional and your mileage may vary. I also do tint swirls which really help hide my screwups. I'm sure better glassers can do this without any sanding. Good luck. I'll be doing another tint lap / cut lap this weekend, now that my resin order showed up at my door a few minutes ago :)
Check the archives for more info, but yes, you can lightly grind or sand down the lap line, or gently press it down into the foam before the resin totally cures, which should be shortly after you cut your lap. The best tool for his is a wallpaper seam roller, but I’ve used my fingertips, a stir stick, and lots of other things.
When you done more than a few cutlaps and worked out all the little details, tricks etc.; You will reach a point wherein your skills will be such that you will not have to sand or grind your laps. Until then baste your lap edge with lam resin as soon as you cut it. Then grind or sand it. Once around the block with the die grinder. Lightly though. Basting, a clean tuck, and a sharp razor blade will help alot.
I’ve been doing vacuum bagged cut laps for a long time now… Unfortunately the laps are hard as a rock when I need to remove the tape due to the board’s time spent in the bag… Another aspect is the fact that all my boards are skinned with either Core-cell or Bamboo, so the “wall paper” roller idea is pretty much out of the question…
I learned to “double tape” the lap area from someone here at Sways… It used to be slow and difficult to get a perfect cut line before I tried this …
I lay down my quality 1/2" wide 233+ tape where I want the lap to end, I then lay down a second layer of “cheap” tape directly over top of the “good stuff”… This results in a very distinct cut line after things harden up…
After the board is removed out of the vac. bag., I lightly score the glass at that raised tape edge… Then I lift up tha glass that has free lapped ouer the tape and the 2 layers of tape separate… I carefully run a razor knife between the 2 layers of tape holding the blade at an angle… All the heavy excess glass is now gone, and you’re left with approx. 2 to 3mm. of glass overhanging the lower 233+tape… I simply get out a flapper disc attached to my drill or dremel tool and sand down this over hang to the tape.
You can slightly feather the edge at this time, then peel up the tape…
It’s harder to describe than it is to do… But the 2 layers of tape is the key factor, the top layer which is sacrificial, and the lower to protect the underlying glass job… Double tape off has helped speed up my cut laps considerably… Thanks to who ever it was who posted it so long ago…!
Vac bagging laminates involve a certain amount of “no touch” time, unlike hand laminating… My system works for the way I laminate, It’s not for everyone…
Wow! I'm not a V-Bagger, but that is a very good solution to the problem of trying to cut a lap when you can't control the fact that resin and cloth have set hard. Very good indeed!.
Thanks Mcding…
I’m not a pro builder, just an avid "hobbiest ,
I like to sit and think things through, and these hardened epoxy situations have worked out well…
Most guys cut lap when the laminate is semi cured… Once you put the lapped board into the bag, you have a hard time controlling / observing the cure rate of the lapped edges,
If you take the extra time and effort to lay out the perimeter of your lap, then double up the tape line, you’ll have some really good “cut laps”…
Howzit don, When I was taugh how to deal with cut laps we used a surform to take down the edge but only used the very end tip of it and it was like only 1 or 2 of the holes then I started using the curved one and oh so much easier. Those were in the days when I lived where rust wasn't a factor that would leave a nasty brown edge on the glass. Aloha,Kokua
Sounds like a nice trick!