UnPossible

UnPossible

Well Known Member
Hey - quick question about everyone's favorite topic - primers... I am finishing up the fiberglass work around my canopy. I am planning on flying the plane before painting it. I have applied and sanded several layers of microbaloons around the front of the windsheild and the targa strip. At this point I have very few pinholes.

Should I just fly it like this (hoping to fly in May-June and will likely paint in the fall or early spring)... or do I need to put some sort of primer on the glass to protect it?

If I do, what sort of primer should I use? Please note that I do not have the equipment to spray any paint/primers.

Thanks,
Jason
 
Me too ....

I have - more or less - the same question as Jason. What kind of primer is best to use on the FG parts to allow me to fly it for a year before getting a finish paint job? It should also be a primer that won't have to be sanded off when finish paint time comes.
 
It is nearly impossible to go wrong by spraying a good two-part epoxy primer to seal the surface.

Anything you spray now will need to be scuff sanded later, at least, before paint. Chances are your paint shop will need to do additional surfacing work anyway.

Don't think any single-part rattle can primer will do much sealing.
 
DanH said:
It is nearly impossible to go wrong by spraying a good two-part epoxy primer to seal the surface.
Click to expand...

Dan, do you mean the same class of epoxy primers you'd use for corrosion protection on aluminum, like AKZO 463-12-8? Or a different class of product?
 
primer/pin holes

Another method is apply a good quality Urethane filler/primer. You can put it on with a small 4" foam roller, really work it into all pin holes. You will be suprised how many pin holes you had & didn't realize they were there. Knock it down with some 200 grit & apply another layer till you are satisfied with the surface. Your surface won't be spray finish perfect, but good enough to go flying with, this primer will be sanded down when you final paint the plane anyhow.
 
DanH said:
It is nearly impossible to go wrong by spraying a good two-part epoxy primer to seal the surface.

Anything you spray now will need to be scuff sanded later, at least, before paint. Chances are your paint shop will need to do additional surfacing work anyway.

Don't think any single-part rattle can primer will do much sealing.
Click to expand...

Any suggestions for the guy that does not have the equipment to mix and spray epoxy primer? Would something like Smooth Prime (which I believe you can use with a roller) work or is there something else that would work better?
 
Last edited:
UnPossible said:
does not have the equipment to mix and spray epoxy primer?
Click to expand...

Jason,

All you need is a cup to mix epoxy primer and any spray gun will do. I suppose the limiting factor might be an air compressor, but even that doesn't have to be anything huge. Pretty much anything other than a 'pancake' compressor will work fine for this purpose.

-Jim
 
This may seem like a rudimentary question, but ...

... how do you clean the spray gun and related gear when using two-part epoxy paints? Is a special solvent required? (I've not used two-part epoxy paints before; can you tell?)
 
roee said:
Dan, do you mean the same class of epoxy primers you'd use for corrosion protection on aluminum, like AKZO 463-12-8? Or a different class of product?
Click to expand...

I'd probably use something from the same manufacturer as my intended topcoats.....the one-system approach, always a safe bet. If you're not painting yourself, call the painter you plan to use and ask.

Rupester said:
... how do you clean the spray gun and related gear when using two-part epoxy paints? Is a special solvent required?
Click to expand...

Most use plain 'ole lacquer thinner. MEK is a little stronger.
 
I've applied an Interlux epoxy water barrier paint to my sailboat - not exactly an apples to apples comparison, but since it didn't need to be sprayed and held up fine for the 11 years I had the boat, mostly outside, it's worth considering.

It is difficult to get a fine finish with a foam brush, but the paint sands and recoats nicely. With several coats sanded it gave a good finish. It cures very slowly and its pot life was longer than I needed.

I used it on a cabin floor, several inspection ports and the engine cover, all fiberglass parts. It took abuse, UV and is worth considering. The only caveat is that except for the engine cover it never got terribly hot, and that only got warm.

Dave
 
Rustoleum

Rustoleum has a new product out. 2-part epoxy primer in a spray can. I happened to stumble on a web page describing it while looking for something else: http://www.rustoleumibg.com/product.asp?lvl=P&pnv=2&snv=1&pid=281

I haven't tried it, I have no idea how well it would work for fiberglass, and in any case it's not cheap. But if you only need a little bit, and don't have spray equipment, it might be worth considering. According to the product data sheet, it too needs to be scuff-sanded if recoat happens more than 24 hours after initial application.
 
Alternative - Epoxy skim coat

Face with similar issue, I chose to skim coat glass parts with epoxy. This appears to be a good way to fill pin holes before applying primer and paint. With that in mind, I will apply several coats, each before the previous one drys, and leave the sanding for priming and finishing until I have the plane painted, after phase 1 testing. The skim coat will serve to protect the glass.

John
 
Smooth prime works great. It's a catalyzed primer that is water-borne until cured, so you can clean things up with water. It is compatible with most urethane paints and primers and is an excellent pin hole filler. doesn't smell bad either. I used a small high density foam roller from HD and threw it away when I was done. You can put on 3 coats in an hour and a half, then wait a day to sand it smooth. If it's not smooth enough, roll on 3 more coats. It dries in about 20 minutes, but wait a day before sanding. This should be a good protective covering while waiting for paint. Make sure you fill the pin holes and seal it up if it's going to be a while. Dirt and oils can get into a non-sealed composites and make it difficult to clean appropriately before priming and painting later. If necessary, you can roll on a couple more coats of smooth prime and sand just before painting. I kept the catalyst in the frig to preserve it. Good luck.
 
Last night I squeeged on a couple of coats of raw resin... planning on sanding that down tonight and using UV SmoothPrime to get me by until I get my plane painted later this year or early next year.

Reading the instructions for Smooth Prime, they tell you to wipe down the soon to be primed surface with their "Prep Wipe".... well I have the primer in my hands, but did not order any "Prep Wipe".

Is there anything special about "Prep Wipe" or can I just clean it up real good (soap and water, likely followed up by a wipe with denatured alcohol), or do I need to order "Prep Wipe"


Thanks,
Jason
 
I bought some prep wipe when I used smooth prime on my first airplane. I ordered it along with the smooth prime. On my next airplane, I didn't have any, so I just cleaned things up with a good solvent. Prep wipe just cleans it up and removes all oils so that the smooth prime will adhere. You should also remember to vacuum the epoxy to suck all the dust, etc, out of the pin holes. Then remove any oils that may be on the surface (prep wipe or whatever) and go to town with your smooth prime.
 
You must log in or register to reply here.