# Kilz as primer

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#### troj

##### Wielder Of the Skillet Of Harsh Discipline, Potent
After reading about enough folks doing it, I finally tried Kilz (technically, the Zinsser version of the same thing) as a primer for the first time.

It fills really well, and sands beautifully. So far, I'm really liking the result!

The one problem I've had is on my Launch Missile -- it's peeling off of the paperboard motor vanes. I'm not sure if that's the primer not adhering well to that material (adhesion is great everywhere else on the two rockets I've used it on), or if it's because these are the two that I accidentally left out overnight, and they got a little bit of rain on them.

-Kevin

#### RangerStl

##### Well-Known Member
The biggest problem I have is how it chips if applied too thick. The key is to sand 90% of it off like any other primer.

I've used it many times and have been very satisfied with the results. Vinyl Alkyd Enamels on the other hand...

N

#### m85476585

##### Well-Known Member
Don't spray it too thick or you will get pin holes.

#### RangerStl

##### Well-Known Member
Don't spray it too thick or you will get pin holes.
Yes, and as you get close to the end of the can it seems to be more prone to pinholes also.

N

#### BobCox

##### Well-Known Member
Have you ever tried wet-sanding it?
Once Kilz is dry, it sands off like chalk dust and does not clog the paper too badly. I would not recommend wet sanding it.

(a) It definitely needs to dry thoroughly.
Absolutely.

(c) I sometimes find it good to spray on the Kliz, let it dry completely, sand, then apply a more "conventional" primer coat.
I almost always do this. Kilz is great for filling deep spirals and wood grain. However, even after being sanded it still has a chalky texture and an off-white color. Conventional primer tends to be smoother and give a brighter white that makes a good base for other colors.

Don't spray it too thick or you will get pin holes.
Since I always end up sanding off most of the Kilz (except what's in the spirals and the wood grain), I don't worry too much about pinholes. The biggest penalty I have found with thick Kilz is that it takes longer to dry.

Yes, and as you get close to the end of the can it seems to be more prone to pinholes also.
I find that I get the worst pinholes when the can is brand new and still has lots of propellant. I have had fresh cans that almost knock the parts out of my hand when I start spraying them. When that happens, the Kilz is usually very thick and sorta foamy-looking.

##### Well-Known Member
I have never tried Kilz as a filler primer, so I am curious why you would use it since it takes so long to dry before you can sand it. I recently tried Dupli-Color Filler Primer, high build formula. I bought it from a chain auto parts store. It dries in about 15 minutes and sanded without any clogging. The filling properties were ok and the price was not too bad maybe around 4-5 dollars. The best part is you can prime seal and paint in one afternoon.

#### troj

##### Wielder Of the Skillet Of Harsh Discipline, Potent
I have never tried Kilz as a filler primer, so I am curious why you would use it since it takes so long to dry before you can sand it.
I'm finding the comments about drying interesting, as they don't match my experience, at all.

I used the Zinsser version of the same product, and was able to sand it later the same day. It's shellac-based, and dried significantly faster than conventional spray paint.

-Kevin

#### RangerStl

##### Well-Known Member
I'm finding the comments about drying interesting, as they don't match my experience, at all.

I used the Zinsser version of the same product, and was able to sand it later the same day. It's shellac-based, and dried significantly faster than conventional spray paint.

-Kevin
I have *never* been able to sand it the same day. Are you in Phoenix or something? It is possible that I have got in the habit of laying it on too thick. I always have to wait a significant amount of time for it to dry.

Could you post a photo of the can you use? I'll edit in a pic of one of my cans later this evening after I get home.

N

#### Peartree

##### Cyborg Rocketeer
Staff member
Global Mod
I've used Kilz before but I've not purchased the kind in a spray can. I already had a gallon can in my shop and since it's water based it thins nicely to any desired consistency, sprays well through my cheap airbrush and cleans up fairly easily. I normally allow overnight to dry (it does get gummy if you sand too soon) and it sands to a fine powder.

Did I mention it was *really* cheap to use this way?

#### RangerStl

##### Well-Known Member
I gotta start doing that. I have an air brush.

#### troj

##### Wielder Of the Skillet Of Harsh Discipline, Potent
I have *never* been able to sand it the same day. Are you in Phoenix or something? It is possible that I have got in the habit of laying it on too thick. I always have to wait a significant amount of time for it to dry.

Could you post a photo of the can you use? I'll edit in a pic of one of my cans later this evening after I get home.
This is the stuff I used: http://www.zinsser.com/product_detail.asp?ProductID=10

It's shellac based; they also sell a water-based (blue label), which takes a LOT longer to dry.

-Kevin

#### troj

##### Wielder Of the Skillet Of Harsh Discipline, Potent
I've used Kilz before but I've not purchased the kind in a spray can. I already had a gallon can in my shop and since it's water based it thins nicely to any desired consistency, sprays well through my cheap airbrush and cleans up fairly easily. I normally allow overnight to dry (it does get gummy if you sand too soon) and it sands to a fine powder.
There are two varieties of these primers -- water based and shellac based.

Water based will take longer to dry -- water evaporates much more slowly than the alcohol base in shellac does.

Perhaps that's the difference in drying times we're seeing -- some of us are using shellac, while others are basically using latex.

-Kevin

#### RangerStl

##### Well-Known Member
OK there's one difference. That's not Kilz. That's B-I-N.

We're not even using the same product. :confused2: They might be more different than we think.

N

#### BillatPSP

##### New Member
I have had the best results with Kilz primer when I warm up the spray can first in a water bath or ??. This helps the primer flow better and flash faster to prevent runs and pin holes. Also, if you set up an "oven" to cure the Kilz, this helps the sandpaper clogging issues. I live in the NorthWest so have to deal with the lower temperatures and humidity. The Kilz flows better out of the can at 85+ degrees.

BillatPSP

#### Peartree

##### Cyborg Rocketeer
Staff member
Global Mod
Welcome aboard Bill!

#### troj

##### Wielder Of the Skillet Of Harsh Discipline, Potent
OK there's one difference. That's not Kilz. That's B-I-N.

We're not even using the same product. :confused2: They might be more different than we think.
Yup, I thought I'd been specific that I was using a Zinsser product, not Kilz?

Are you using the shellac-based, or are you using water-based?

I may pick up a can of Kilz and see if there's a difference.

-Kevin

#### RangerStl

##### Well-Known Member

I've got the white spray can with the red writing.

#### powderburner

##### Well-Known Member
I wish all you guys could step back and read this thread as a non-participant.

It's actually kinda funny.

#### Solomoriah

##### Well-Known Member
The vapor that the Kilz primer from Wal-Mart releases smells sort of fruity to me; but it makes my wife and daughter sick. Literally, they get sick, headaches and nausea, if I bring such a rocket near them within a day or so.

It lays down too thick a coat to suit me. The cheap stuff I use normally lays down a coat that's really too thin, but I just put two coats on, 15 minutes or more apart (for some reason, that works better than one heavy coat).

#### troj

##### Wielder Of the Skillet Of Harsh Discipline, Potent
I found the difference!

From the Kilz website:

Originally developed to replace pigmented shellac sealers, KILZ Original primer/sealer has a powerful stainblocking formula that handles most interior stains, including water, smoke, tannin, ink, lipstick, pencil, crayon, felt marker, red wine, dark paint and grease. It even seals the odors caused by pets, smoke, and nicotine.
Kilz is oil-based, not shellac-based. That's why you have to give it so long to dry. But I suspect it's similar, other than the base, which is why the result is similar.

So, go find some of the Zinsser stuff, and I bet you'll find it dries much faster!

-Kevin

#### powderburner

##### Well-Known Member
Something that has bugged me is whether oil-based stuff (like KILZ) will do any damage to the airframe materials as it soaks in. I don't know for a fact that it does cause any damage at all, but I would like to see some test data or something to demonstrate that body tubes, fin materials, glue joints, etc are not impaired at all, or only have reduced strength of XX %. I don't know how volatile the oils are, possibly they evaporate before they have much chance to soak in, but again I would like to see some numbers.

Not to take this thread off-track, but I have the same comments about using Rustoleum-brand paints (which were advertised at one time as having some kind of "oil" in the formulation to soak into rusty stuff and help stop further corrosion).

Seems like this could be a good NAR research project for some energetic young person to construct a bunch of samples/coupons and do some calibrated pull-testing.

#### MarkII

##### Well-Known Member
I had some Krylon Stain Blocker spray paint that was left over from a ceiling repair project and I used it on a rocket last year. I obtained results that were similar to what Kevin described of Zinsser (and others described for Kilz). It did take considerably longer to dry than standard Krylon primer does (something like 48 hours, as I recall), but when it did, it was very chalky when I sanded it. Another thing that I noticed was that it seemed to add more weight to the rocket than other filler/primers do. With a fair amount of sanding, I did get a very smooth surface, but it still remained chalky, so I covered it with a coat of a more conventional spray primer. I worked pretty well as a filler for small, shallow grooves, too. It wasn't quite enough to make me want to switch to it from Dupli-Color high-build primer, though. The heavier weight and the longer drying time were the primary cons with it.

MarkII