Removing foam strip backing

[diy_fun_uk]

I'm preparing door frames for someone ahead of the doors being replaced and frames painted. The door frames had foam insulation strips on them (manually applied to the surface of the stays to keep drafts out.) I've removed them as best I can, however the tacky backing strip and some of the foam remains.

What's the best way to remove this? Chemically (and if so using what) or do I give it a go with my oscillating tool with sanding attachments? My thoughts on the latter are the tackiness might cause sandpaper to clog up very quickly and be rendered useless.

Any advice/tips welcome

 

[foxhole]

Depends on how old it is, lighter fuel destroys many adhesives, though if its decayed then sharp knife followed by sanding.

 

[diy_fun_uk]

Depends on how old it is, lighter fuel destroys many adhesives, though if its decayed then sharp knife followed by sanding.

Thanks. It's old, probably been installed for 30+ years. I'm not too bothered if the actual (very thin) adhesive strip is left on, as long as I can get all the gunk off and leave a tacky free surface for painting.

 

[Tigercubrider]

Lighter fluid

 

[StephenOak]

Chemically (and if so using what)

My first go-to is white spirit, that dissolves an awful lot of adhesives. If that fails I use meths.