sanding primer... does it matter if it is brushed or shot?

[bob branch]

I'm finishing a plane and have it ready to apply Brodak white primer to it. Does it mater if it is brushed or shot? Most all is going to be sanded off is it not? I plan on following it up after sanding with silver prior to appling colors.

bob branch

[Will Hinton]

I personally feel you're better off to spray the primer, and all coats after getting the beast sealed for that matter.  You will thin the primer to spray it and more will gas off, hence be lighter in the long run.  Also, brushed surfaces willl often be "ridgey" and thus require more effort to sand smooth.  I also recommend you use Polar Gray for a blocking coat rather than silver.  It, too, is lighter, and will do just as good a job.
All the spray advantage is negated if you use an UHLV gun and don't thin, of course.  But she'll really build up faster!!
Blessings,
Will   

[bob branch]

Thanks Will. Think I'll shoot it.

bob

[Ted Winterman]

        I usually brush the first 1 or 2 coats very thin first, which from the pressure of
brushing will usually force the primer into any small pinholes.
        Spraying does'nt usually have hardley any pressure and may just lay on top. After
brushing you can apply as many spray coats as you think you need, then sand.
     
       Ted

[bob branch]

Ted

Thanks. I noticed a number of unfilled pinholes on the horizontal stab and wondered how to get rid of them. Think I'll brush that area then sand it down again. I love the way the brodak primer sands.

Bob Branch

[Leester]

I had that problem with pin holes even after dope and talc, I put on a little rejuvinator just on the pin hole worked.

[john e. holliday]

I am confused after reading all these posts.  Isn't there a difference between filling an priming a surface?  I myself use talc and dope for filling the grain and putty for the places that need it.  Then I spray a primer coat to block any discolorization that is on or in the surface.  I also sand the primer to get a smooth surface.  Then the base color goes on followed by trim/graphics.  DOC Holliday

PS:Maybe that Arizona weather is getting to me.

[bob branch]

John

The Brodak "primer" is a sanding filler. I think its an errant name myself. Its essentially like a dope and talc and sands like it. I'll be using the silver to mask color like you use a primer. Good point though. Glad someone else was bothered by it. Don't think its the Arizona weather. Sorry, another excuse down the tubes.

Bob Branch

[bob branch]

Ty

May you be blessed in heaven.

bob

[phil c]

John, there isn't any difference between filler and primer as they are used here.  Autobody types always use a primer, which is a thick, filled coat you sand down to level the surface.  A true paint primer is a paint with a lot of vehicle and not much color used to improve the bond between the base and the color coats.  Autobody primer does both jobs.  So does clear dope with talc or stearate filler in it.

If you spray auto primer in thin, light coats, nearly dry you can get a very quick build up that is pretty light and sands very easily.  It makes very quick work of the priming/filling/sanding step.

[Bill Little]

John, there isn't any difference between filler and primer as they are used here.  Autobody types always use a primer, which is a thick, filled coat you sand down to level the surface.  A true paint primer is a paint with a lot of vehicle and not much color used to improve the bond between the base and the color coats.  Autobody primer does both jobs.  So does clear dope with talc or stearate filler in it.

If you spray auto primer in thin, light coats, nearly dry you can get a very quick build up that is pretty light and sands very easily.  It makes very quick work of the priming/filling/sanding step.

Very true!  *Most* automotive primers are "primer/fillers".  They have solids that helps to fill scratches and other minor imperfections.  A great auto Primer/Filler to use is Duplicolor "Filler/Primer" in the big spray can.  Just make sure you sand it down to the "freckle" stage.  Only leave that which is in the imperfections.  You can also buy it in "bulk" to spray.  All the Auto paint suppiers sell a similar product.  On the high end paint jobs, the painters get the primer mixed with the pigments of the final color coats.  You can do this, also with the lacquer based primer/fillers available to us by simply adding color to the mix. (not as good, but definitely helps)

Dupont sells a product called "Fill 'n' Sand" by the quart and gallon.  It comes in red oxide and light gray.  I love it!

If you want a super light finish, I use Nitrate clear (with a blue tint added) to attach the silkspan and fill all the "wood" areas.   I do not add anything to it since Nitrate has more solids to begin with.  If you let it cure between coats, it works are good as anything else!

As to a blocking coat, Silver has been used for years.  I agree with Billy Werwage, and do not want to risk the poor adhesion of the silver (basically Sig Silver) so I use a very light gray to "block".  It does not have to really be a totally opaque coverage.  Just enough to cover.

Use a very light colored blocking coat under reds, yellows and whites.  Silver will give a gray cast to these semitransparent colors.

Wow, I wrote a LOT!
Bill <><