[jackking123]

I am using grey Kirker Primer on much of the plane as needed... on critical areas, not for show but protection.

However cockpit area RV-7, interior (visible side) I am priming with same, but the grey is a bit too dark. It is a medium to darker grey. I bought a GAL of the Grey. I am happy to paint the cockpit with primer and leave as is (primer no top coat). Not using top coat of paint (talk me into it) More on that below decision below. But back to mixing White into Grey.

Bought a QT of the White Kirker Enduro Prime to mix with Grey. I have used about less than 1 QT of the GAL of Grey so far. I could just dump the Qt of White into the 3 qts of Grey (in Gal Can). However I am stuck with that. I DO want to have a formula that is consistent.

However mix as I go adds a little at a time. However this makes the mixing process each time a little more tedious, and may result in inconsistent batches. It is doable. This way if I want I will still have the DARK and WHITE to shoot individually.

My plan (correct me if I am wrong) make a small batch, 1 Part White, 3 Parts Grey to start. Catalyst is 1 to 1 with primer as usual. Reducer (slow cure down optional which I have and would use in summer). f that ratio works great, have my formula. If not:

• Start with 1 Part White to 3 Parts Grey
• If too light add more Grey: 1 Part White to 4 Parts Grey.
• If too dark add more White: 2 Parts White to 3 Parts Grey

THOUGHTS?

CLEAR COAT? YES, I could top coat it with "PAINT". Not doing that. The primer looks nice, goes on nice, even if slightly darker (but can fix that). I'm going to leave as-is, primer in cockpit. However considering a matt clear on-top of primer for protection, but that is a different story. If I do that I have to shoot the clear about 45 to 120 min after primer to get "cross link" bonds. The clear will provide UV protection and make it more durable (but weight and cost go up). Also clear can be touched up for wear and damage. HAS ANYONE SHOT CLEAR OVER PRIMER? I am only doing this with parts you can see in the cockpit and then only the visible side of that part.

BTW KIRKER IS OK WITH MIXING COLORS OF PRIMER AND CLEAR OVER PRIMER, Chemistry wise.

My plan to save time and effort is BATCH prime as many of the structural parts (visible side that will show in cockpit area) before riveting together. I am sure there will be defects, scratches during construction. but those can be corrected. The ideal of prepping the surfaces and priming off the plane is appealing. I think the quality will be better to BATCH prime before assembly. Also seeing the unpainted rivets will be cool. Ha ha. THOUGHTS?

 

[wirejock]

I've never sprayed clear over primer, but I've seen several clear over rusty patina to preserve the perfect rusty look.

I did paint everything before assembly. I wanted fasteners to be visible. Plus it's easier.

Buy an empty paint can. Use 60ml catheter tip syringes to measure. Easy to duplicate or adjust tint.

They told me I had up to 5 days to apply final paint and to shoot paint 24hrs later so there's plenty of time to off gass. Always worked for me. Otherwise, there's no way to sand the primer to a perfect 800 grit smooth finish.

Coats of primer or paint were 1 hour apart.

Keep us posted

 

[BoydBirchler]

My guess is, it will be easier to clean if you apply clear coat, because the surface of the primer is purposely open to aid adhesion of top coats.

 

[jackking123]

Thank you.... testing is key. I have primed parts I did 10 yrs ago that look great, although different brand of primer, akzonobel paint. Good stuff but it cost x2 or more... $210 to $320 for Gal... Good stuff. Also it was the perfect (to me) grey... It was grey grey... not too light or too dark.

I am looking forward to making a custom color grey primer. The syringe idea is a great, not sure I am going to get that precise. I will look at getting one.... I have 3M cups with disposable liners, and there is measuring scale on those cups. I will mix up 2 to 4 oz. I will start with 25% white, 75% grey. Not to waste primer, can still shoot parts, that don't show if I can not tweak that batch.

At this point I don't know the effect of the White. It may be 10% it may be 50% to get ideal grey? I am not that picky. If 25% / 75% is close I will do that. Math is simple. If it all goes sideways. I will shoot white alone (where it is hidden) and stick with the stock grey color. No worries. Adding white will make it lighter. How much TBD.

Clear over primer is an idea TBD. Getting less than a Gal of clear is an issue. A Gal of clear makes 1.25 Gal. That is way more than I need. I am only doing cockpit.

As far as 800 grit I am not doing any color sanding. Clear does smooth out base coat (of top coat), and it will do the same for primer... It will NOT be gloss. I am going for MATT finish, no gloss, no semi-gloss or satin.

But bottom line the plan is no sanding, prep aluminum well, abraded, etched, clean, shoot one primer coat to cover... Done. The clear must be shot after (within 45-120 min) to get max adhesion. You can re-sand (Scotch Brite), clean, shoot more primer then clear. That is not the plan, too much work, but is an option.

The clear would increase durability. Bottom line it will look nice (to me) either way (I hope). Ha ha.

 

[jackking123]

My guess is, it will be easier to clean if you apply clear coat, because the surface of the primer is purposely open to aid adhesion of top coats.

You are saying it will get dirty, will attract dirt and wear, get scratched. True and not really. Any painted finish primer or paint can wear or get scratched. Primer is very durable, not shinny. I want matt. Yes in the first month it is still curing, especially the first 24 hours.

Primer stops "absorbing" and being chemically active after many days, weeks, months. You can not (should not) paint primer after the 100% cure time without abrading and cleaning. Why? Paint will not bond to it well. So yes and no, it will not be a sponge for dirt or wear.

It is TRUE Primer is not meant for a TOP COAT... Top coats will be better, be it single stage or base coat clear coat. However my two part epoxy primer is far better than rattle can. Also surface prep is key. I abrade everything with Scotch-Brite pad and etch, dull finish and "Water break free", i.e., no contaminates. Primer is durable all on it's own. But surface prep is really key to good longevity.

Again primer is not shinny. I want that flat look. The CON or one thing about primer is it has no UV protection in it's chemistry. In direct sunlight over years (decades) it will fade and start to look faded or poor, not fresh. Cockpit is somewhat protected from weather and sun. Still there is no doubt time will change it in some way. Fade may be minimal or pleasing, or not. Clear provides smoother finish and UV protection to paint or primer, and what I was discussing. No doubt clear is a bonus, but is it worth the expenses and time. Again clear must be shot in a short period after shooting the primer so they bond.

Plan B is after X years, cockpit primer finish is looking worn, faded, shabby, take all removable parts out of cockpit area, prep and shoot with something, be it primer, primer + clear, primer + top coat... For structure riveted in, pain staking prep, taping and re-shooting it in "in place" or "SITU" . FUN!!! Many people shoot paint in the cockpit after plane is built. It can be done. My hope is the primer will be easy clean (solvent) and touch up will be easy, and the cockpit will look nice as long as I own it. Not worried. No need to over think it, just build it.

I am not putting a lot of upholstery in besides seats (already have and they are grey) and arm rest. I will put padding or cover on side will, where seat belt buckles might bang against side of fuselage. Also carpet will be a thing. This is the plan for the plane. Like Nike says: "Just Do It". I appreciate the comment because it forces me to really think about the Pros and Cons... I am OK with primer only, or primer plus clear...

 

[Gusmax]

After sufficient flash, ENDURO PRIME may be topcoated for approximately five (5) days with no
sanding required. After approximately five days, epoxy should be scuff sanded before topcoat
application

 

[jackking123]

After sufficient flash, ENDURO PRIME may be topcoated for approximately five (5) days with no
sanding required. After approximately five days, epoxy should be scuff sanded before topcoat
application

Roger that... Thanks for the info. I read spec sheet... and talked to Kirker what they said.

SPEC Sht​

​

DRY TIMES:​

Set to Touch: 3 hours minutes at 70°F​

Full Cure: 2 to 3 days at 70°F​

​

RECOAT​

ENDURO-PRIME may be top-coated after 30-60minutes, depending on shop conditions,​

up to two to three days, also depending on shop conditions.​

After this window, ENDURO-PRIME must first be scuff sanded before top-coating.​

I noticed in my cool shop this winter, keeping it around 58-62F cure times slowed way down.
At 50F and less cure time take much longer. Kirker said don't go below 50F.
To your point if temps are in the 55-60F range s/b OK, but I can plan on doing it within 3 hrs.
Summer time with 90F times are very short (unless you add reducer).

It is not a tragedy, you just have to scuff the surface. However this goes against my do less work policy. Ha ha.