1) Heat Gun or Propane
Torch (the types you normally see)
2) Stiff Non-Abrasive Plastic Scraper of some type (vinyl shops have these - cheap)
Remover - "Goof Off", "Rite Off" or any number of brand names. All pretty much the same. Available at hardware
stores. Spray bottle.
4) Isopropyl Alcohol - in a spray bottle.
5) Paper Towels or wipes of some kind.
The key to removing old vinyl is to get it hot. The vinyl will soften and then can be scraped or peeled off depending on it's age and condition.
The safest method is to use a heat gun. The standard type that you would find in a hardware
store (1600 watts or so).
Alternately, if electrical
power is not available you can use a propane
torch - again, the usual type. These have to be used very carefully since there is a fine line between softening the vinyl and scorching the surface.
Regardless of the method you choose, keep in mind that the trick to this whole thing is to get the old vinyl hot enough that it comes up easily. How hot is that? Well it's probably hotter than most people would expect. In general I would say that the surface needs to be heated to something around the boiling point of water (100 deg C) but in practice you should go by touch.
Using a heat gun work a small area at a time. In most cases this will mean working each letter individually. Heat the area in question evenly keeping the heat gun in motion at all times. Occasionally touch on or near the heated area to gauge the temperature. When it becomes uncomfortable to touch you are probably in the ballpark.
Use the plastic scraper to lift
up an edge of the heated vinyl. Often you can grab the edge and peel it by hand very slowly. Older vinyl that has lost
most of its plasticizers will be more brittle and the scraper may be required to remove the entire piece. You just have to do whatever works. Every vinyl application is different depending on how old its, how much UV exposure it has had and the nature of the surface it is applied to.
This is where experience comes in. You want to get the surface hot enough without damaging it. The goal is to raise the temperature of the substrate not just the vinyl. Yet you want to do this without damaging anything. So take your time with the your chosen source of heat. Don't get it too close, keep it moving and be patient. This is time well spent and will reduce subsequent wear and tear on your fingers considerably.
Do not use the adhesive
remover during the heating
and scraping phase. It does nothing at this point and will only make an unnecessary mess.
After the old vinyl is removed there is still more to be done. You will probably notice that some tiny patches of vinyl remain and that there is an adhesive residue on the surface. This is where adhesive remover comes in.
Spray the adhesive remover liberally over the area to be cleaned. Let it work for five minutes or so. Yes, it will tend to run so be prepared for that.
After a few minutes you will see that the old adhesive will soak up the remover and swell to become a soft clear gel. You can scrape most of this off with the plastic scraper.
When you have scraped off the bulk of the old adhesive you may want to re-apply the remover and let it work again.
At this point you can use paper towels or wipes to get the remainder of the adhesive off. Spray the area liberally with isopropyl alcohol first and then wipe. The alcohol really helps at this point since it will dissolve any remaining clumps of goo. Keep going over the surface with alcohol and clean towels until everything is clean.
MAKE SURE THAT YOU HAVE AN ADEQUATE TRASH RECEPTACLE HANDY FOR THE REMOVED VINYL, REMOVED ADHESIVE AND USED PAPER TOWELS. YOU'LL BE SORRY IF YOU DON'T.
That's about it.
NOTE: Old vinyl on automotive vehicles can sometimes leave a "ghost" image on painted surfaces due to various processes at work in the paint
, adhesive and the vinyl itself. I know of no remedy for this short of a new paint
job. I must confess to a limited knowledge of gelcoats and fiberglass
but suspect that it can happen on boat hulls as well so be prepared. I do not presume to give any advice on the remedy.
I hope this is useful. Sorry it's so long.