Getting paint off beams

pineapple

When I last had had a similar job, it was an empty house with stone floors. I used a blow lamp. No problem apart from old smouldering varnish falling on your head.
This time it's in my very lived in lounge! Previous owners put horrible cladding on the beams. Underneath it looks like just one coat of paint.
I've got some Nitromors that's supposed to stick to vertical surfaces. Alternative seems to be a heat gun. But I'm told they eat electricity. Also it's an old cottage and there is a faint possibility it might be a lead paint. How can you tell? Advice please!