I’d read the sticky at the top of the page regarding 2k which is what had made me not think about doing itA few members answered a lot of my questions around setting up to spray 2K in the sticky thread at the top of this forum.
Our smart repair guy said you have to change the masks every few uses if the filters are looking blocked, but he’s only using the 3M filtered ones, same as I used with my EpoxyThere are countires where charcoal filters are approved (or were) for isocyanate, but you need the right one, I think it's APEK1, but please check, also I believe they need to be changed regularly as the isocyanate damages the filters.
I remember reading that sticky 2k warning thread and something in there doesn't add up.
That was always my theory that a charcoal mask may not seal properly. Also trusting employers to regularly change charcoal filters is a risk. However air feed is also a risk if someone connects to wrong outlet and breathes in unfiltered oil mist from there compressor... it's happened before.The purpose of the air fed mask is to ensure that any leak is outwards not inwards. This is through the air pressure inside the mask being higher than outside.
There is no dispute that it is possible to have a filter that removes isocyanate. But if you wrinkle your face differently as you breath in air might bypass the filter and come around the edge. I know this risk is real as it happens very occasionally when I am spraying other paint.
I’ve got to stitch weld in some repair panels where I’ve got some rust/rot to cut out around window frames etc.How are you welding them?
If plug welds I use a zinc rich epoxy primer, the reasoning being some of the zinc might hang about and do some good.
If using a spot welder, then nothing at the site of the welds and epoxy zinc or epoxy mastic where it won’t be affected by the weld.
Spot welds need really clean metal.
I use BH Electrox - high zinc primer - on the back of patches. Seems to work OK. I have used the Upol weld thru primer but I don't think it's as good as the Electrox as an actual rust preventing primer. If I was buying stuff from scratch now I'd buy the BH Etchweld too as it's their proper weld thru primer. Not cheap though and for me there came a point where I needed to make do with what I had rather than spending more cash.Does anyone recommend a decent weld through primer to put on the inside of panels before I weld them in?
That is interesting and makes sense in relation to some other coatings I have used. The epoxy primer I use does not have different mixing ratios for wet on wet. It may be interesting to give it a try with a bit more thinner. Currently, the only time I use more thinner is for very small mixes that are going to be applied using an air brush.The higher thinners content is to get a flatter finish because you won't sand it.