using undercoat

[stayclean]

using a white undercoat on some doors , can i thin undercoat down to make it easy to apply
any help would be apperiated

 

[iblob]

Yes you can. Assuming it's a solvent based product, use white spirit. The amount you should use depends on the quality of the chosen paint. For example, Dulux New Work undercoat is a very thick paint and does need more help to flow than an own brand undercoat.

Start by adding a capful of spirit to a litre of paint, in a paint kettle. If the brush is still dragging, add a little more. Just don't over do it, as you will just end up with a wishy-washy finish that will need another coat.

Another (specialist) option is to use Owatrol. This is a Scandanavian made product. It is an oil that is used to assist the flow of solvent paints without reducing its body. It is usually added in extreme temperatures where paint tends to become gloopy. It is also a primer for rust covered metal.
It's not cheap and not readily available. But some Dulux and Crown-Brolac decorating centres do stock it. It comes in 500ml tins and costs around £12 (the last time I saw it).

 

[billyo]

iblob, at £12 for 500m it costs £96 for about a gallon you could get 3 gallon of undercoat and 3 gallon of gloss for that, and thin till you get what you want