Best strategy for spray finishing large doors

[fobos8]

Hi everyone

I'm fairly new to spraying and I need some advise on the most efficient and effective way to apply 4 coats of waterbased lacquer to some 400x2000mm maple veneered wardrobe doors. My spray booth is 3x3m so I reckon I could comfortably fit 3 or 4 in at a time. I need to finish both sides and all four edges.

My initial thoughts are to lay them flat, spray the edges first and then do one surface, allow surface to dry and then flip to do other surface only.

Does anyone else have some better ideas/experience doing this sort of thing?

Many thanks, Andrew

 

[engineer one]

since no one else seems to have taken up the baton, maybe i can try to offer some help.

laying the door flat will i think make it more difficult to get a good finish.

i would suggest doing the edges and the top and bottom by holding the door vertically in a wedge, then having done all the edges, you can spray one side and the other. then once dry turn over and start again.

if you are going to put them up vertically you ought to think about pushing
pins into the stand and supporting the doors on them so that the smallest
possible surface sticks through the varnish. these pimples are
easily repaired later.

you might think about laying the doors are 45 degrees might also be helpful. i think you would get less running if the doors are horizontal rather than vertical.

paul

 

[Scrit]

I find it easier to spray vertical surfaces evenly than horizontal ones (it also seems to produce less nibs to be removed), so ideally if they can have eyes inserted into to tops or bottoms I'd do that then hang them. That way it would be possible to spray the lot in one session. The damage caused by the eye holes are unlikely to be noticed, especially if at the bottom of the doors where they're unlikely to be felt. In any case they can be filled

Scrit

 

[engineer one]

sorry scrit, must get my terms right.
to me vertical is with the long side up to the ceiling whilst
horizontal is with the short side up toward the ceiling
so you are actually only spraying something which is say 3foot
high, not 6.

i guess others may think horizontal means lying the thing flat on the
floor or bench. like you i do not find that that works.

i also find that having to spray at about waist height and up,
also makes it easier to get a more controllable finish and also
the spray pattern is easier to do.

one long sweep is better than many short ones., and probably will cut
down the runs that might occur.

scrit is there a more sensible way that we can describe the direction
of doors as we talk about them, ie which way is height etc??

paul :wink:

 

[Scrit]

I just think in terms of orientation of the piece as you spray it. I agree that longer strokes are probably better than shorter ones but as a 6ft plus person I find it straightforward enough to spray 6 to 7ft tall pieces. If the doors were pre-drilled for cup hinges it would be possible to rig-up some hooks to hold the doors via the cup holes and hang them so that the long edge was in the horizontal plane then spray the surfaces with long horizontal sweeps....... :? That way would mean no pimples, repairs, etc at all.

Scrit

 

[engineer one]

i agree scrit, and thinking more i feel there is often a feeling that you have to spray the whole door. i often wonder whether there is some sense in
hand painting / staining the edges because they tend to be more absorbent than the faces, and it is easier i think to load the brush properly,
and ensure that you get a more even surface and finish, then coat the faces. :lol:

like many people i find that the corners can be places where you get a build up which is difficult to keep thin and not too runny.

also make sure that you have the finish thinned enough, and are using a spraying thinners to ensure the finish is smooth and adheres properly.
do not use hand painting thinners to spray,it does not work properly.

paul :wink:

 

[fobos8]

thanks a lot for your replies everyone - after a few days I wasn't sure I'd get any!!

I reckon hanging them sounds like a good idea, especially from the hinge holes. I've got old steel clothes rail knocking around so I'll use that.

Once again, many thanks :wink:

 

[fobos8]

Hi everyone

Its interesting that all of you say that the doors should be sprayed in a vertical plane as oppose to a horizontal one.

So far I've spraying most things on a "turntable" or saw horses, i.e. in a horizontal place. I always seem to get some dust nibs though.

As a general rule is it better to spay things vertically? I'm pretty new to this so - so please excuse my ignorance.....

Also, when you hang things how do you comfortable spay the underside edge withought "do a limbo dance"? Maybe I've misunderstood what you guys are saying. Should I do edges and then hang?

Cheers, Andrew

 

[engineer one]

glad to have got the ball rolling.

i suggested this idea of hanging up, or standing up for
two reasons, the most important being actually if you think about
it, the surface open for things to land on is smaller.
next i talk horizontal meaning the long side parallel to the ground.
just because for mere mortals who are not quite 6 ft tall, it is
easier to reach the ends, whilst getting a smooth straight spray pattern.

if you have done the thing laying down, then you do not get a build up
on a constant level all across, and also as i have said the surface for things
to settle on is bigger.

as for doing the ends and the top and bottom, thin bits,
i still recommend the first couple of coats done by a brush, to
ensure that you get proper absorbancy cover.

if you are not careful when spraying these narrow pieces, you get build
up at the edges on both the bottom, and the lower edges of the main
faces.

remember, rather like planing a long length of wood, so they tell me. :lol:
you start beyond one edge, and walk slowly or move your whole arm
slowly and in as straight a line as you can, that way you get a smooth
finish, drop down about 2/3rds the distance of your first layer, and do the
next, then again, this way, you will more easily blend the
coats, and the lines will be less distinct.

hope this helps
paul :wink: