Removing sail numbers

I work at a sail loft and have found no easy way to remove sail numbers besides just ripping them off. As for the residue, we rub white marking chalk where the sail is sticky. This method seems to neutralize the adhesive and give the residue a white color. This method is especially useful if you first cover as much of the old residue as possible with new numbers. The remaining small areas can then be covered with the chalk. Hope this helps
...sailmakers also sometimes use solvent to soften and remove the residue--start with dabbing mineral spirits to soften the adhesive,,and carefully use a putty knife to lift the goo.--some say lacquer thinner or acetone is fine but I'm not so sure.....
The best way I've found is to peel the numbers right off then use a solvent called "Goof Off," found at Home Depot or anywhere really, to remove the residue. I usually dab with a cloth on the spots and let them sit for a minute or two. Then I give the cloth another swig of the Goof Off and start scrubbing. Goof Off is powerful stuff and not wanting to damage the sail, remember, a little solvent goes a long way. I think some sail makers may agree that acetone is a bit too powerful.
Acetone will not hurt the sail. This was recommended by Vanguard. I also used Acetone 15 years ago to remove a decal from a main sail on a laser 2. The sails I removed old sail numbers from where raced all summer with no effect to the sail. Acetone works the best. Put it on a cloth and start rubbing.



The following is a cut/paste from email reply I sent out some time ago.

Acetone is more effective the longer it is left on the sail, softening the glue residue. Since it's so fast to evaporate (hence the warnings about harmful vapors ), the trick to making it work is to keep it as liquid against the number and glue.

We usually start by pulling off as much of the numbers as we can, then we go after the rest with acetone. Start by putting a acetone proof barrier between the sail and floor, grass or whatever surface you are using. This will trap and keep the acetone on the back side of the sail and glue. Next be very liberal in wetting out the sail around the numbers with the acetone. Acetone will not damage the cloth used for Laser sails (or pretty much any dacron sailcloth material w/ or w/o a finish on it) I'm roughly guestimating I would pour out about 2 cups worth per side. Finally, get some toilet paper and put it top of the numbers - the paper will hold the acetone against the numbers, slowing down the evaporation. Let this sit for 5 minutes or more. If the toilet paper starts to dry, add more acetone. Rub a test area (we always wear gloves) with more tp or paper towels - when the glue has turned soft, you can use either more paper towels, or a 1" putty knife to scrape off the residue. It may take a second "coat" to remove every last drop, but with this method when it's done, you won't know that a number was ever there.

MEK (the liquid hardner used with polyester resin) will also work well, but it tends to be more expensive then Acetone
Hi All,

Please be very careful with acetone! It can kill you, even when wearing gloves! At least wear very heavy gloves, not the thin surgical kind.

That said, be sure you need to remove the numbers? A used sail for club racing may not be worth the trouble, or expense. Sometimes you can change one digit, so the RC can deal with two boats that are the same. Or digital eights can be easily modified by adding or removing a few pieces? (My new boat has 4 8's, so that will be my choice in the future.)

Many recommend the solvent go on the backside, as it might penetrate the sail better than the number, thus reach the glue you are trying to soften. And to finish with some talcum powder to whiten the final residue, so it doesn't collect dirt over time.

More at:

Al Russell 138888
Just a side note: acetone works very well for this application. I removed my old numbers, and replaced them, just this past weekend. It still takes some elbow grease but it did the job without leaving sticky residue. As far as the safety of acetone, it will collect in your liver and kidneys over extended times of use throughout your life. The more important danger is how you handle the fumes. It is very flammable so don't forget about your water heater pilot light that may be in the garage. Also use heavy gloves that are made for solvents. A simple respirator should also be used if you are indoors or without adequate ventilation. Here is a copy of the Material Safety Data Sheet (MSDS) from one of the manufacturers if you have an interest:
Here is something for the Europeans to the point of removing sailnumbers:
I´ve changed the sailnumbers of two sails this year with "Dr. Beckmanns - Fleckenteufel". (See the little bottle in the attachement to this reply.).
It is very soft to the sail, but aft work, there are shaddows be seen on the sail - everywhere, where this fluid had contact that cloth.

First I thought they never go away, but aft sailing each of this sails and doing some capsizings the shadows slowly went away - nothing to see now from that shadows :)

I carefully pulled off the old numbers and took 2 hankerchiefs. One was under the sail and one I took round one of my fingers, made the fluid on it, and then polished immediately the old glue of the numbers away. One bottle (here ~ 2 Euro) is enough for 12 numbers, if you spend it few. You can get it from (Also somewhere in their onlineshop, I guess)

Good work


I didn't know acetone is dangerous.. I did work experience in a boat workshop and we actually used acetone to wash our hands. Yeah, we'd clean up figerglass messes and then clean our hands thoroughly with it afterwards.
LooserLu said:
Here is something for the Europeans to the point of removing sailnumbers:
I´ve changed the sailnumbers of two sails this year with "Dr. Beckmanns - Fleckenteufel". (See the little bottle in the attachement to this reply.).
It is very soft to the sail, but aft work, there are shaddows be seen on the sail - everywhere, where this fluid had contact that cloth.

First I thought they never go away, but aft sailing each of this sails and doing some capsizings the shadows slowly went away - nothing to see now from that shadows :)...
this following pic´s I made during the changing that (from relpy #10) old numbers last summer.
I planed to make a to make a short-report for drLaser and he got already that pic´s. Unfortunately I had no time until now to write all down, but I think this whole thread substitue such a text. So I decided to make my pic´s public here and I hope the help a bit (That fluid-shadows, that are seen at the pic´s, gone away aft a hard day´s sailing - with several capsizings):








Acetone is not beer of course, so you shouldn´t drink it, like a Forster´s-Lager :D.
A 6%-solution of Vinegar (Acetic Acid, that you maybe find already in your kitchen...) is more toxic than Acetone, but it also doesn´t kill you (neither the Forster´s I hope...). If you wear gloves while working with Acetone for a longer time and be a bit carefull with your breath, then you will survive it, I guess. Thats all to say from my side to this aspect.


P.S.:Jackson: did you got my Emails? Please contact me, anyway.Thx



I just changed numbers on 2 sails, both had digi-8's so a few numbers I just added segments to. All I can say is:


Goo Gone is great stuff, citrus based with a small amout of petroleum distillates, and available in US hardware stores. Safe, no gloves needed, ventilation reccommended. I soaked from the back first, for a minute or two, then used a hair dryer on low to peel the number, then soaked the residue for another minute, scrubbed it and repeated this. Hosed the sail, then put numbers on when dry. It works on sticker goo, or duct tape goo too!

Please leave the acetone for the professionals.

Al Russell 182797


Chuso007 said:
I always have washed my hands with acetone after working with fiberglass.... And/or turpentine also for paintbrushes and so...
There's been some discussion on TLF of the harmful effects of acetone, so I googled it. The US Department of Health and Human Services has this to say. The possibility of birth defects sounds like reason enough to avoid it. So practice safe sailing, y'all:

Health effects from long-term exposures are known mostly from animal studies. Kidney, liver, and nerve damage, increased birth defects, and lowered ability to reproduce (males only) occurred in animals exposed long-term. It is not known if people would have these same effects.

How likely is acetone to cause cancer?The Department of Health and Human Services, the International Agency for Research on Cancer, and the Environmental Protection Agency (EPA) have not classified acetone for carcinogenicity.

Acetone does not cause skin cancer in animals when applied to the skin. We don't know if breathing or swallowing acetone for long periods will cause cancer. Studies of workers exposed to it found no significant risk of death from cancer.
This is an old thread but I thought I'd weigh in, just having done this.

I wanted to avoid the harsh stuff so heeding the advice of someone above, picked up some Goo Gone from Home Depot.

After trying it on a portion of the glue residue of one number I was not impressed. It seemed to be leaving an oily residue of it's own.

So I went back and bought acetone. Night and day. Acetone works much more effectively and evaporates quickly with no telltales. To deal with the quick evaporation I put an old piece of poly (vapour barrier) underneath the sail and then after spraying (I put the acetone in a spray bottle to keep it to the working area as much as possible) I placed the other sheet of poly on top and let it sit for a few minutes.

I found the following process works well:

1) Spray liberally and sit for 3 minutes with poly on top
2) Lift poly and spray again lightly, then immediately scrape residue with plastic scraper, working inwards from the margins of the residue so to not spread the glue residue elsewhere. This gets about 75% of the glue residue. Use paper towel to scoop up the blob of residue before the acetone evaporates
3) Repeat #1
4) Repeat #2. This gets most of the remaining residue.
5) Repeat #1
6) Now using a bristle brush, scrub the area vigorously. You may see little "beads" of glue residue scattered about. Pick the up quickly with paper tower. Once the acetone evaporates, they get sticky and are harder to pick up.

That's it! Note I did this on a dacron sail. I've no idea if acetone is safe on mylar. I worked with rubber gloves on and in a ventilated area but even then I probably killed a few brain cells. If one is really concerned then wear a respirator.

It's also worth noting that even after this process, I can still see a faint shadow of where the numbers used to be. I'm not sure how noticeable it'll be but my plan is to put new numbers over where the old ones were so hopefully it won't be too noticeable.