Edit: My mate Steve asked about paint thickness. That's not really too much of an issue with heat guns. The gloss doesn't peel in layers, it all comes off back to the base because the heat causes pockets of air to expand between the gloss and the wood. It's not melting the paint. All the gloss layers come off in one go, because they act like a plastic film that's floating on a pocket of air.
Decided to time attack a door jamb this morning. To the heat gun finish took about an hour and half working about as quick as the gun will peel it. I also found it much easier to work uphill, so the waste heat would prewarm the paint ahead. If you have some coordination, you can be holding the gun and sweeping it over the area ahead as you strip with the knife, so there's no wasted time.
It actually helps if the paint has a second or two to cool after being bubbled, since it makes it less likely to go gummy when peeled and more likely that it'll all come off in one strip.
I picked up some paramores stripper (DCM, dicholoromethane & methanol) for 20 pounds from toolstation.com my favourite place in the world - they're cheaper than everywhere I've checked, screwfix included. If your order exceeds 10 pounds, you get free next day shipping. You also get free tea and coffee while the staff collect your order in the warehouses. :^P
The doorjambs are going to need a multisolvent treatment to get them nice and clean I expect. The heatgun leaves little flecks of paint stuck that are just annoying to pick off one by one with the gun, so the chemical stripper is a smart move after 99% has been heat peeled. The stripper pack says it's fine to start from the first coat, which means you'd waste a ton of stripper compared to using the heatgun, then using the chemical method for the last stages of cleanup. I probably spent about 8 - 16p on electricity for the heatgun, versus pounds or tens of pounds if I'd used the chemical stripper from the start.
Buy a wire brush from TS for 96p and give the door a brush down to get any loose flecks off when they're cold.
Doing this kind of stripping with paper, I wouldn't have finished one jamb today, would have a very sore arm even if using a sander and be down a lot of paper. The paper would also not get into the details anywhere near as well as the heat gun - which works sound as a dollar pound. In fact, it'd tend to sand them down, which is what I'm trying to avoid by stripping instead of going straight on with another gloss coat over the old.
In terms of gloves for chemical stripping, you can have a look at the following guide:
Basically, for acetone you want in order of degredation resistance from best to worst:
Unsupported neoprene or natural rubber, then a combination of the two is next best
For DCM (stripper), you want:
Suppored PVA (NOT PVC)
That's right, PVA, like woodglue. Maybe you could just paint PVA all over a pair of more accessible gloves. It's not as suprising as it sounds. DCM likes attacking nonpolar things like oils and greases. PVA is water soluble, and water doesn't like grease or oils.
The best option is just to work so it doesn't drip on you and dry your skin out. Neoprene gloves are easy to find, PVA isn't so easy. The odd drip on your hands won't hurt you at all.
The white stripe you can see left on the door jamb is emulsion, which won't bubble off with heat.
The correct term for oil paint is alkyd paint. The oil is the solvent in the paint. It evaporates off slowly and then the paint oxidizes and turns into a film by a process called crosslinking, where the paint molecules join up into a network. Emulsion (latex) uses water as the solvent and an acrylic as the binder - it doesn't really have latex in it. When the water is gone, the acrylic binder ties the paint into a network. You can scrub the emsulsion off with water, but it's very hard work once the acrylic has set into a network.
There are three parts to paints. The pigment, the solvent and the binder or vehicle. The pigment is obvious. The solvent is also kind of obvious. The binder is the real difference and in this case is crosslinking oxidation for gloss and acrylic resin for emulsion.
So what? Well, that's why gloss takes weeks to dry even when it's gone all sticky, the paint is oxidizing in the air. Emulsion dries in hours because only the solvent needs to evaporate for the film to form into a network.
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