What a sticky mess!

[John Bion]

Hi all,

I have just cut and engraved a display board made from 9 mm Baltic Birch Plywood, which I had pre-stained and varnished. Prior to engraving, I masked the entire board 900 mm X 600 mm) and post engraving I sprayed, firstly with primer and secondly with several coats of black paint. All good, so far.

I have just stripped the masking off to continue the construction process, only to find that the masking tape has left a gummy, gluey, sticky mess on the board which does not want to come off anytime soon. Added to that , the paints seem to have slightly shrunk the masking tape which in turn has led to some bleeding of paint outside of the engraved area.

Has anyone got any suggestions as to what I may try use to strip this gum off without stripping the acrylic varnish?

This is a job I am already behind on :eek:

Thanks for your suggestions.

Kind Regards, John
322624

[Mike Null]

John

Citrus cleaner will do the trick but if you have some mineral oil or cooking oil handy give that a try.

Do not use alcohol as it may attack the acrylic varnish.

[John Bion]

Thanks Mike :)

[Dave Sheldrake]

IPA John, it won't damage the acrylic but will dissolve most types of detritus if the citrus cleaner doesn't work

[Kev Williams]

I've found alky will attack recently cured paints & such if used aggressively, but does work work on the goo--

I've also had good success with mineral spirits and naptha with soot and goo.

with any of these, test first if possible!

[Ross Moshinsky]

How long did you let the varnish dry? Typically you want to take what the mfg recommends for drying time and triple or quadruple it if you're going to be masking. You really want your clear coat to be dry as possible.


As for the bleed; what kind of masking are you using?

[John Bion]

The Varnish had a day to dry, I knew I was pushing that, but the time scale is tight. The tape is regular ‘cheapo special’. It seems that both heat and paint thinners affected the tape, I won’t use this ‘non-brand’ again!

I have a tale to tell though, and it is all Mike Null’s fault ( I have to blame somebody), Upon receiving his recommendation to use citrus cleaner, which I do not have, I stopped trying to clean around the text with earbuds and other cleaners, and rushed out to the supermarket to purchase some citrus, still with my stubby pencil behind my ear. After queuing for 10 mins in the “Quick-Queue” at the shops, with everyone smiling in a very friendly manner at me, and I also could not help notice the check-out girl trying to contain her mirth at a private joke, I rush home to get on with the job, only to have my daughter start giggling at me ..... and ask me why I had an earbud behind my ear :) Oh well, at least it was a clean one I had absent-mindedly tucked behind the ear. So Mike, if you had not recommended Citrus cleaner, I would not have provided unwitting entertainment to other, it MUST be Your fault :)

Kind Regards and thanks to all, John

[Chris DeGerolamo]

What about simple green?

[David Somers]

Hey John!

This is likely not helpful in the UK, but I will throw it out there anyway.

Ray Scott over at Rabbit Laser USA has suggested the masking tape from Harbor Freight. It is a cheap paper tape that is low tack. I have not had it gum up on me yet. I have seen it up to 2in diameter.

For larger needs I have used low tack mask from sign supply shops. Around here you can get it in 1000 yard rolls in a wide ranger of widths. The roll I bought a bit ago was 18in at 1000 yards for roughly $60 US? The brand was Conform from a company out in New Jersey in the US. I did find it worked well on the CNC too provided I slowed the travel rate of the bit down. Move the bit too fast and it shreds the mask.

Hope that helps.

Anyone tried what we see marketed as Frog Tape? Wonder if that would solve John's problem with the tape pulling/shrinking back?

[Mike Null]

John

I am surprised that the girl at the supermarket didn't suggest using using water to clean your citrus.;)

If I am color filling birch plywood or any other "white" wood, which I try to avoid at all costs, I spray the engraved area with a clear sealer. That prevents the bleeding of the paint into the grain. I also use a wall paper roller to press down the mask after engraving.

[John Bion]

Thanks all for your help/s.
The client has just collected the completed project and is thrilled with it, so “all’s well that ends well” ;)
Hope you all have a great weekend.