cut laps

Hi, ive glassed one board free lapping and ive just been thinking if i should start cut lapping my future boards. what to you guys do? is it hard to cut lap? is it really only nessecery when using tints on one side of a board?



its not neccesary to cutlap a clear board but they do look better under lights. also its excellent practice for when you do want to do a tint. it does take a while to get them perfect so if you do a tint and you havent practiced you will most likely end up with a inch wide pinline lol. do all your f$cking up on clears where it doesnt matter.

you know your doing it right when you thinking the board doesnt even need a pinline

If you dont mind wasting tape do it to all boards.

But Silly is right. Good practice for tints and pigments.

You also end up with a nice distinct lap line on the deck as well which can be seen under a highly polished gloss coat.


ahh but is not wasting tape if your learning something tho, darren

i spose a complete gumby that cant learn anything would be wasting tape :wink:

here don this is what a cut line should look like

hey guys

im gona sound really stupid asking this....

but can someone give me a run down on the difference bewtween 'free laps' and 'cut laps' ? Ive been wondering this for awhile as I have seen reference to both but have never been able to work out the difference...I assume one type (free) is where the glass is just cut and lapped over the rail, whereas the other (cut) is when the glass is run up to a taped edge on the deck and once cured is 'cut' back/off before the deck layer of glass is done?


thanks again


no such thing as a stupid question! and yes your exactly right


From one beginner to another: definitely get started learning cut laps. I’ve done 4 so far (all epoxy). I am getting better but still have a long way to go. A couple things I’ve learned so far:


  1. You need to use good tape or it won’t stick to the foam. I use 3M 233+.

  2. Cut with razor blade before the resin is totally hard. After it’s sticky, but before it’s hard.

  3. Use the good tape only for the outermost or 2 outermost tape layers. Use cheaper tape and masking paper for the inner layers and to mask off the rest of the board. Saves $.


Now, there are alot of things I would like to get better at, so here’s where I still need work:

  1. Laying a nice, smooth, reasonably symmetrical tape line. I do it by hand/eye. Looks ok but far from perfect. A tool would be cool, but hand/eye even better.

  2. Cutting without gouging the foam. Gouging the foam fills in with a darker color when you are tinting. This can be covered with pinlines but personally I love the look of good cutlaps without pinlines. Something to shoot for.

  3. Getting a uniform glass-lap in corners and nose area. I always get bunched up or no-glass in these areas. Needs to be sanded down and messes with the color uniformity on tints.


Good luck…


tape two pieces of foam cut-offs together in an ‘L’ shape.  measure the distance you want your lap to be (2’’ or whatever) from the inside edge of the ‘L’.  push a tongue depressor (or craft stick) through the top part at the mark for your lap line.  the tongue depressor will make a slight indentation which you can follow for your tape line and will not be visible on the blank after the tape is pulled.  wrap the side of the ‘L’ that will be in contact with the rail of the blank with masking tape so that it will slide down the rail without hanging up.  i am trying to develop my eye so that i dont have to use a tool but this tool has helped me in the past.


i also share the problem of bunches or gaps around the tail and or nose, so frustrating.  i hope someone comes along with some handy hints for avoiding this problem. 



thanks merret, that makes me feel a little I wasnt as stupid as i thought not knowing the difference between cut and free laps, in  fact I knew all along but didnt know that I did! ha!

any chance of getting someone to gimme a rundown on the cut lap ok with the free lapping process but would be keen to get an idea of how to go about doing these cut lappie thingys!

u in melbourne aust merret? im on mornington peninsula!

cheers M

hey fullas i think its better without the marking tool . the reason why is that modern foils look better when the lap line tapers at the nose and tail. i make my laps the width of the tape so you looking at the tape as you are masking and looking at the rail , so you site along both and keep the space the same width as the tape. and you narrow it as you get to the nose and tail. the laps look a lot better optically as you have an illusion of the laps getting fatter if you dont taper them.

the trick is to pull tape when the resin is gelled stiff but not hard. about 2 hours with poly maybe 6 with cut with the blade on its side with light pressure on the lap as you pull the tape forward on an angle toward the stringer

heres how i clean the lap with a surform, it take about 10 minutes

taping back a while ago i think i tape better now

but you tape toward yourself so you can site the rail and width



laying the blade on its side with pressure on the lap prevents the lap lifting as you are pulling the tape. this method will leave and inivisible lap on a clear board. if you cut too late the lap will be visible as the glass bruises

wrt nose and tail , you need to get your cuts right in the cloth so there is very little overlap. tricky.

and also after you lam and lay the laps over you need to go over them with the squegee again to remove excess resin as the glass floats in the resin makes it impossible to cut cleanly . this occurs the worst in the nose so requires more care at the end of laminating to get them down with no excess. wipe the excess resin on your stand or i have a clean rag handy

All the tools are on sways but if you can afford it by the master glasser video. It's great if you are like me and don't know any shapers to watch do it. There is a lot more than just cut lapping on there so I think it's worth it.



resintintJimmy001-1.jpg picture by tjrm63 Practice makes perfect


resintintJimmy001-1.jpg picture by tjrm63 Practice makes perfect



It sure does


no worries,

yeh sure am, eltham area.

whereabouts are you on mornington peninsula?


langwarrin south, surf mainly peninsula, island and beyond