Epoxy Primers

General Composites Discussions Products Talk
#1

Looking for a substitute to Duratec primer for epoxy projects.

Found that House of Kolor makes 2 products that sound like they are what im looking for.

KWIKURE EPOXY PRIMER (KP21)
KP21 is a 2.1 VOC hi-solids catalyzed Epoxy Primer that meets all current air quality regulations. It is designed to be the first primer applied to bare steel, aluminum, fiberglass, magnesium and galvanized surfaces. It’s strong adhesion, hi-build, excellent durability, and corrosion resistance make it the logical choice for the base of a long lasting paint job.

CHROMATE FREE EPOXY PRIMER (KP2CF)
KP2CF is designed to work over properly prepared aluminum, magnesium, fiberglass, galvanized steel, OEM finishes, and some woods and plastics. It’s strong adhesion, fast build, and ease of sanding (wet or dry), make it a logical choice for the base of a lasting paint job. It may also be applied to repair areas for fast filling touchups.

Dont understand the difference between the two ?

edit * Chromate is a rust inhibiting primer. Used primarily on aircraft. It’s a olive green to light green in color.

But anyway - since HOK is pricey, kept looking & found a hotrod site that had lots of guys saying good things about this 2part epoxy primer product.

http://www.southernpolyurethanes.com/Product%20lines.htm

Sticks like glue & sands easy - I think this would work well for finishing urethane foam plugs & top coats ?

http://www.hotrodders.com/forum/epoxy-primer-question-46638.html

#2

Duratec vinyl ester products.

#3

SOB - This Epoxy vs. Ester is making me crazy…

Can one find a “happy medium” using both or is it one or the other ?

:mad:

Looks like another order to USComposites…:eek:

#4

There’s no problem. I’m not sure what you’re confused about.

Just don’t try to bond ester based resins to cured epoxy unless you prep the piece really well. Epoxy sticks to pretty much anything though, including cured ester based resins.
You can use a poly or vinyl ester gelcoat, and lay up epoxy on it.

#5

I guess the biggest problem im having is making items with epoxy resin & trying to get a smooth finish on the surface using compatible products.

Since ester does not generally bond well to cured epoxy then im trying to stay away from that & use epoxy stuff to finish the surface.

I got a boat load of Epoxy resins that I need to use up & no ester resin.

Guess its the situation im in now so I figured just try to master the epoxy side of things first…

Just need a sandable final surface coat & a tooling gelcoat substitute that I can lay up on but im getting there through testing.

Thanks for the help.:smiley:

#6

Is this for coating the plug, or the mold and parts?
There’s no good reason for using epoxy on a plug. Make the plug out of wood, plaster, urethane foam, etc… and spray with poly or vinyl ester coatings to make it smooth and shiny.
For mold and parts, the surface coat goes down first, so it’s fine to use poly or vinylester products. Once that cures, both ester and epoxy resins will stick.

#7

I was hoping it would work like Duratec on the foam - etc.

So far sanding epoxy is like :eek: but these auto body guys say that 2 part primer sprays / sticks / sands great (for epoxy).

BUT - Will it give the same smooth surface Duratec prime / clear mix ? Probally not im thinking now.

It might take more surface work to make it glass smooth to pull molds from ?

Ah - Need to stratagize a bit.:o

  • Helpful info again TET - Im willing to try it if you think might be worth a try ? Joined the PPV section to help out, waiting on my password.
#8

So I take it you are working with epoxy on urethane foam? Is the epoxy brushed on? That would be a PITA to make smooth.
Duratec surfacing primer with hi gloss additive mixed in comes out nice, but generally still requires some sanding to make smooth because of the type of gun used to spray it. Automotive-style 2 part primers come out smooth and even when sprayed with professional spray guns, but the primer isn’t glossy.
I finish plugs with Duratec black hi gloss coating. Similar to the primer, but much thinner, harder, and even shinier. Minimal sanding to make “glass smooth”, and molds come out beautiful.

#9

Im working on two projects at the moment. “quite ambitious”

  1. Foam Airbox - “still just foam”

  1. Extra Ram Air Scoop - (Pure Epoxy / F-Glass / Fillers)

Now for my first project its a miracle ive got this far & the results are very good but damn theres alot more to do.

The airbox is going to have to be 3 parts (at least) then tied together. My plan is not great.:o

The scoop though just needs a glass smooth finish ?

#10

To smooth out a resin coating, try after applying the resin to shake it to smooth the coating out!