Putting new decals over old.

If you want the new decals to fail even faster than slap them right over the existing decals.

Just like anything else in life, a key to everything is having a "good foundation", old decals are worn out, unstable which ultimately will result in damaging anything slapped on top of them.

Good prep by removing old will reward you with the longest life of your new decals.

There are specialized decal adhesive remover tools and chemicals that will make the removal and cleanup job go smoother..

If you don't want to put the time and effort into doing the job right, take it to a body shop and pay the price to get the job done correctly.

You can supposedly remove the decals with a heat gun and putty knife. I'd try that first.

I agree with Gdetrailer on this. Do it right the first time or you will be doing it again.

Yes you can use a heat gun and scraper to remove the decals. The trick is to get ALL the adhesive off also.

I’d also remove the old ones first,,but if you’re putting matching decals on, they will last just as long on top of your current decals as they would otherwise and presumably look right.

That would be Goo B Gone.

Gooma wrote:
Yes you can use a heat gun and scraper to remove the decals. The trick is to get ALL the adhesive off also.

Yes, a heat gun and plastic scraper blades (Titan is one brand) will get 98% of it off. And 3M makes an adhesive remover that can take the remaining glue off.

Yes on the heat gun and plastic blades. But be careful to not overheat with the heat gun. Wave it over the decal for a few seconds then take it off and try the scraper. If not loose wave for a few more seconds. the vinyl will go from stuck tight to easy to peel to way too soft to peel very quickly.

And be careful on the thin siding on RVs and heat guns. They’re more susceptible to scorching or yellowing than painted vehicle panels or boat gelcoat.
Removal can involve any number of methods. Heat gun (sometimes I use a propane torch if handier), razor blades, fingernails, putty knives, eraser wheels and various solvents, from lacquer thinner/acetone to adhesive remover, wd40, gasoline, goo gone etc. I generally prefer stronger solvents. Less scraping and elbow grease.
Get your technique figured out on less conspicuous areas and know that it takes a smidge of sense and coordination to take heat and a razor blade to your vehicle or RV.

We used a hand-held hair dryer and a putty knife to remove decals that had begun pealing on our RV. Just took some time, a little physical effort, and then used goo b gone to get the glue residue off.