tool for cutting lap

Hello all, some respite from the sniping that’s been too common here lately… I’m curious what anyone is using for cutting laps, particularly on tinted or opaque lams. I’ve done a lot of cutting using the odd utility knife, single edge razor blade, Xacto, or whatever’s handy. Correct timing is of course a necessity, not too early, not too late, but jest raight, as Rap would say. However, if I cut too deep, there’s a chance the foam will tear, the next lam won’t fill/penetrate/seal the hole, and if a lighter color, down the road the cut sometimes shows something bad. What I’m looking for is a simple off-the-shelf solution that, provided with a sharp blade, is easy to guide, cuts the exact correct depth and no more. I’ve seen Jack Reeves opaque lams against a clear deck that were flawlessly cut, and didn’t need any sort of pinline to disguise them. How are these done? TIA

ive cut my few with a regular new single sided rasor. seems liek when i catch it at the right time it cuts like butter and doesnt even sink into the foam much. kinda gotta use that artists steady hand and itll end up straight. what si the amtter with your lap line? dj

assume you get your timing right, and cutting with a sharp blade is easy enought BUT… You don’t want to cut too deep for reasons already explained, but the razor which we have both used wants to “track” that is, to follow the weave of the cloth particularly where the weave is at a slight angle to the direction of cut. If you’re cutting a colored lamination, and you do it very nicely, you won’t need a pinline to cover the cut line. Most of the time, though, the hand is not steady enough to perform this only-one-chance job, and do it right the first time. I think few of us can accomplish this, and I speak from long years of experience. I ask to find out if anyone has something slick which makes this simple job easier.

Make a jig out of hardwood that holds the tip of the blade just exactly the depth of the glass laminate. Run the jig along the lap line and voila. Sorry, couldn’t find one to take a picture of. The trick is to design the jig so that the blade is exposed out the back so you can see your cut line clearly. The longer and narrower the jig, the more control you have. You can even get real creative and make a rail-guide for perfect reveals. Rinse any dirt/debris that sticks to the lap with acetone. There is a tool from Fein that ocillates and has a fiberglass blade that could be used to cut the lap after it has cured hard. They have a slick depth guide and the tool is easy to control.

Hey It’s not the tool, as you will soon find that you peel up the cut glass as you cut, adjusting blade tension as needed, and never cutting into the foam. Very few of us can lay down the tape line perfectly curved, even from the rail peak, even from side to side. If you can lay down that perfect curve, the lap cut is the easiest part of the equation. Not saying that I can, but was the pinstriper and layout man.

TAPE: Use black tape and remember that the better you can get the tape line the easier it is to cut. Also try to leave between a .5" - 1" overlay on the tape with the cloth. For cutting i use a regular old razor blades. Box of 100 will cost you about 6 bucks. They make a tool that will let you slide a razor blade into the end of it and that is useful at first. Always use a fresh blade. Sometimes you might want to use one blade for half the board and then get a new fresh one for the other half. Timing is as critical. too early and the glass will pull. Too late, then the glass will be very hard to cut. I wait until the lap is 40% cured and make a very light cut right along the tape line for the entire lap. If you have a good tape line then you have the perfect cutting guide. then after about 75% cure, I take the tape and begin to peel it off using the razor to slice off any glass that did not get cut the first time. You can hold the razor at a parrallel angle to the foam to avoid risking cutting into the foam. Above all else preperation and patience is what will seperate a good trimmed rail from a truly magnificent, no pinline needed rail cut. Go slow. If you think that you are already going slow, then go even slower. You’ll be amazed what patience and concentration can do for craftsmanship. Lastly, for inspiration go see some of Greg Hunts work, Tyler’s boards, and Cooperfish, even some Jacobs come out with Flawless rails cuts. Drew