Ghost lap again

I know there os a post already about the same problem but maybe someone can clarify better?

I keep geting ghost laps showing.
I add some pictures if anyone want to check
Here is what i do just in case i am Doing something wrong
1- laminate bottom 1 layer cloth
2- sand the lap on deck to stay smooth.
3-blow with compressor
4- laminate deck 2 layers cloth.
5- clean the lap on bottom
6-hot-coat deck and bottom
7-sand everything 200grt
7-another lighter hot coat.
8-sand all the way up untill 1200 grit with water.

Cheers and good waves

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I can’t see anything in the pics - what are ghost laps, and why are they a problem?

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Ive just had the same problem (board # 2 and 3) and would love to know a solution. Im using an almost identical process.
Hope to find an answer🤙

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Hello Mr. Huck,

If you zoom in maybe you can see them.
Ghost laps are shadows ( kinda grey, smoky)
When you laminate the bottom and then do the deck they show up, its kind of that you can see the lap under the lamination ( shadowy, grey, smoked)

I work with silmar resin uv treated and shaper fiberglass so i am almost sure its not the materials because they are what industry uses.
I add another picture maybe its more clear.
I see many people with this issue.
Cheers and good waves.

As cloth layer thickness increases, optic refractive index changes/differs.
In the dark ages, I did one 6-oz bottom, one 6-oz top and a 4-oz deck pad not wrapped. Deck pad (shadow) could always be seen.
Rarely have I seen a board where you cannot see the underlying rail lap.
Caveat, I’m not a pro-glasser.



It all makes sense, but i did a 7" mid that the ghost lap was only visible on the left side, this pisses me of a bit! cause obviously i did well on the right side of the board.
Now i don’t have the photo here i have to do some digging to find the photo.
I will upload it as soon as i find it.
Cheers and good waves.

From the pictures I’m not sure exactly what the issue is. Regarding the resin and cloth mentioned by the OP, I use the same resin, keep in mind that the resin stays a little green for about 3 days after glassing and becomes more clear as it fully cures. The laps are more visible during this time. I pay attention to this color change because it is easier to sand the board while its still green.

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Well it sure happens!
And it is visible on the end product.
I am starting to suspect is something that happens after sanding the first lap.

I am going to try the following,

1- not only blowing the sanded areas but also clean them with alchool.

2-i am going to fine sand with 300 grt after the first sanding with 100 grt and then clean them again

3-let the lap dry longer 24h00 instead of 12h00.

4-going to be extra carefull with the scissors when cuting the fiberglass to make a straight line.

I will let you guys know as soon as i laminate next board

Don’t fine sand you laps, you need to cut the hard fiberglass cloth, not polish it and mash it. use fresh sand paper…sand with 100 grit and then do the hot coat. also as you get better at lamination you won’t need to prep the laps…and your hot coat will never need to be sanded into the weave. next if you don’t want the white ghost to show through, get some styrene and paint the spots where you have sanded…then hot coat, or sand…or what ever. Also when doing that fancy color work chit some people put a layer of 4 oz over the entire board, and then sand that down flat n smooth…never hitting the color work / weave.


Yea. I barely sand the laps at all. Just knock the high spots and sharp edges off with 60 grit.

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I will stick to that, cheers and good waves.

Cheers and thank you.

I do freelaps, i would not even try to do cut laps, i can sense the mess a cutlap would be from what i have seen some friends doing in the backyard.
Anyway i send another photo of another ghost lap hope you guys can see it now.
Cheers and good waves.

Some brands of fiberglass show the laps more than others, especially with 6oz. Are you sure it’s not a 6oz with a volan finish? Prob would be showing even more if it was, but might want to look into the finish of the cloth.

Also, some of the Silmar resins are optically brightened more than others. The common ones are Silmar 249A (this is best for uv resin) and there is Silmar 249B (which has added blue brightener) and the 249BB has even more extra blue.

If you are using 249B/BB + uv cure + a blank that is optically brightened then it can be what’s showing the cloth. Normally you want to make sure to use 249A for uv resins, or anytime you are doing color work such as tints/pigments.

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How many layers of cloth are you running on the deck side? If multiple layers are you staggering the cuts? I generally do two layers and a deck patch. Deck patch is cut an inch short of the rail apex. First layer is cut right at the rail apex. Second layer has the lap.

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Thank you so much,
Yes probably has to do something with that.
I will choose more carefuly the resin, but yeah i use the BB one.
I will look into it.

Cheers and good waves

Thanks mr. Mako.

Yes i was staggering the cuts because of bad quality scissors, now i just got some better quality scissors, finishing a shape next week, will update the results.

Thanks to everyone for the priceless aid.
Cheers and good waves