There are a lot of primers out there, and I have been doing quite a bit of reading (probably too much, because the more
I read the more I didn't know what to do).
It finally came down to Cortec or AFS primer (see related links), and I finally decided to go with AFS primer / sealer.
The main reason I was looking at these two primers was for the safety aspect. I wanted a product that I didn't
have to worry heavily about the fumes and cleanup. I went with AFS because it is the only primer I have found that is
both friendly to use and is also designed as a sealer as well as a primer. Read on to see what other products I looked
at.
On the rudder I used just regular old Zinc Chromate out of a rattle can, and it seemed to work pretty well. I covered
all the interior surfaces including the interior of the skins and went through pretty much a whole can. Now I put it
on a lot thicker than I really needed to and it would probably go a lot farther if I used it in the future, but its $7-8 per
can. This is not cheap stuff and it really isn't even the best protectant.
So I did some research and this is what I found:
The Zodiac uses 6061 aluminum which is by nature corrosion resistant, but I live in Florida, very close to the Gulf and
I don't want to rely just on that.
The options:
1. Zinc Chromate
Pros:
- Easy to use
Cons:
- price (seven dollars a can)
- not very enviromentally friendly
- not very lung friendly
- Designed only as an adhesion layer, does not seal out moisture
2. Alodine
Pros:
- A dip - that means no messy overspray
- Adds almost zero weight
- One of the most popular and best corrosion protective "primer" layers
- Designed only as an adhesion layer, does not seal out moisture
- Can be used over and over
Cons
- Storage - must store gallons and gallons of it (50 - 100).
- Because it is a dip, you need a container large enough to hold enough liquid
to cover the piece you are coating
- not enviromentally friendly
- not skin friendly
- Must be careful when disposing
- Not designed to be a top coat, really is meant to have another coat
on top of it. It does not seal out moisture. It is an excellent adhesion coat with good corrosion resistant charateristics.
3. Self-etching primers (i.e. variprime)
Pros:
- Easy to use
- One step process
Cons:
- not very enviromentally friendly
- not very lung friendly
- Designed only as an adhesion layer, does not seal out moisture
4. Cortec Wash primer (the stuff Zenith uses and sells)
Pros:
- It is self etching, so it is a one step process
- Price is very reasonable from Zenith ($24 / qt. I think)
- Very thin light application
- Enviromentally Friendly and User friendly - low toxicity
- Can be sprayed or brushed
- It is diluted with WATER and WATER is used to clean the equipment *
Cons:
- It is still an adhesion coat and does not seal out moisture, it was not designed
to be a top coat
5. Aircraft Finishing Systems (AFS) Primer / Sealer
Pros:
- Enviromentally Friendly and User friendly - low toxicity, non-hazardous
- It is diluted with WATER and WATER is used to clean the equipment
- It is designed to be left as a top coat (sealer) and it also is a very affective
adhesion layer
Cons:
- It is not a self etching material so an acid etch must be used before the
primer can be applied to aluminum
- Price is very resonable but because of the etch it does bump the cost up a little
($27.68/qt for the primer and $19.25/qt for the etch which is cut 2 to 1 with water)
- I don't know anyone else who has used it
