Am I beating a dead horse trying to get duratec primer to lay down nice and smooth so that very little if any sanding and polishing is required?
Kind of.
You can thin it with laquer thinner which is all that “duratec thinner” really is. No matter what you do though, it will never come out glossy. All you can do is learn to spray it with minimal orange peel. That will minimize the sanding time.
It can come out like a nice paint job if applied properly. I recommend against using thinner.
With the Duratec surfacing primer, it helps a lot to use 25-50% high gloss additive.
I generally use an ES cup gun to cover large areas, and then sand with 400+ grit.
For tight areas that are difficult to sand, a paint gun is used and minimal sanding is needed later. But it’s tough to cover large areas this way because of the short pot life.
I know nothing about spraying, but I’ve found that you need a reasonably thick even coat for best results… too this, and you’ll need a heap of sanding.
TET, you are talking about the G100 dump gun, right?
What size/# nozzle are you using for this?
I have a prototype 10.5" wide by 72" tall carbon foil I will be using as a plug. Still fairing with West and Microlight filler. I’d like to Duratec both sides within the pot lfe. And, that gun really appeals to me for it’s simplicity and easy cleanup.
…Which brings me to yet another question; How do you think the polished Duratec primer will hold up to actual use on my trimaran. Will only be in the elements/water while I’m sailing. It’s a dagger style rudder blade. I don’t mind the gray color. (At least it’ll be shiny). I’ll be using it after splashing a mold and while I figure out the epoxy/carbon infusion of my laminate schedule.
Any guidance is appreciated.
I spray Duratec surfacing primer using their thinner with a 2.5mm tip gun. And it will always have a slightly textured surface but not much different then automotive high build primers; it knocks down very quickly.
If you want it glossy you should try the Duratec glossy top coat. I recently did a project where I sprayed the high build primer then blocked to 120 grit then sprayed the glossy top coat (thinned and 1.8mm tip) and it came out with minimal orange peel. I did this to save time sanding, I could skip directly to 800 grit then progressively finer, compound, then polish.
The top coat is way less porous then the primer so it would probably hold up better in your application.
BTW – if you’re your spraying over west epoxy resin, they recommended to me to scotch-bright (I used grey) the surface with water before applying the Duratec. Their tech line was pretty helpful.
What gun were you using? I’m not very experienced with spray guns and don’t want to waste material, destroy a gun or make extra work for myself. Looking for easy to use and easy to clean. I do plan on shooting some gelcoat so the dump gun sounds great if it can do a reasonable job on primer, paint and perhaps some PVA.
I’m thinking the water & scotch-brite treatment is to get rid of the amine blush that surfaces from the west. I usually hit hardened west with a mix of water and denatured alcohol and wipe clean before I start sanding; good call, thanks shoe!
I’m using gravity guns, not a dump gun. These have more controllable (adjustable) fan pattern which I find makes it easier to get even coats and fine finish. The gun I use depends on the material, for the high gloss coating (thinned) I use a cheap gun I bought from Homedepot which has the 1.8mm orifice. I use this same gun for PVA. For surfacing primer and gel I use large orifice gravity guns either 2.5mm or 3.0mm depending on viscosity.
I’m sure you could spray all those materials with a dump gun but I’m not sure about the finish you’ll achieve. Especially using regular paint or PVA. Maybe the other guys have more experience with this.
Yep, it’s to remove the amine.
i recommend reducing the primer slighlty and saving yourself some money and buying the 14.99 gravity feed harbour frieght sells.
high air pressure and 75% fan pattern (4"-6" at 8-12") works great over larger areas. to get in tight corners i dot it in and turn the feed way down.
please wear a respirator with organic cartriges. this stuff can really do a good bit of damage to the organs and nervous system.
MEK works great to clean up but its super super bad to spray into the air and breathe in.
if your a novice i recommend a smaller tip size and starting with spraying it with a barely visible fan pattern. if you go in and dump it on with one coat youll orange peel it.
I’d just like to verify this, because everywhere I look it appears as if the hi-gloss additive is listed as being meant for mixing with a gelcoat; there is usually never any mention of it being suitable to mix with Duratec’s own grey surfacing primer. Is it possible? Can I add Duratec Hi-Gloss additive to Duratech Grey Surfacing primer if I’m looking to polish the final layer of my plug to a mirror finish?
Short answer, yes. Just sand it when you are done. If you want a smoother finish use a urethane primer.
Sounds good, thanks. Is it possible to take a 50/50 primer/hi-gloss to a mirror finish? Why do you suggest using a urethane primer as well?
Duratec primers can be sanded and polished, although not as good as the topcoat. Adding clear to it will make it flow a little better. It will also make it harder to sand (not much, but harder). The more clear you put in, the harder the surface and the better it will polish.
If you have a good bit of fairing to do on the plug, spraying with the EZ Sanding primer is best. You can build up thickness and it sands quickly. The Surfacing primer will also build up fairly well but it is a bit harder to sand than EZ Sanding. If you only want to buy one product, get the surfacing primer. It gives a better finished surface.
Great, that’s about what I’ve done. The plug was constructed out of CNC milled MDF but there were a couple of gouges in the pattern, so there was indeed quite a bit of bondo-ing and then I used to duratec to fill the rest. It’s worked out quite well. I’m going to go ahead and order some hi-gloss additive for a final coat of duratec once everything has been knocked level and the sanding action can be dedicated just to getting a mirror finish, instead of leveling.
Does Frekote FMS and then 700/770 work well as a release between duratec and an epoxy tooling coat? I’m planning on vacuum infusing the mold and I’d like to do it with an epoxy system.
Regardless if you mix in some hi gloss additive you will still have porosity issues because of the micro spheres/ glass bubbles in the primer surfacer.look closer , you’ll see them, just Shiney pores…use there clear coatings for porosity free surface.far as using a semi perm release, it will work just fine on primer surfacer with or without hi gloss additive . ve, poly or epoxys compatable.
So I’m trying to choose which duratec topcoat I should go with. I’ve decided against using the hi gloss additive mixed with the primer and am considering going with their ‘Hi Gloss Coating’ (http://duratec1.com/pdf/DS%20602-021.pdf). Is this the most ideal layer to apply to a plug after it’s been sanded and leveled with their surfacing primer? Does any one know where to actually order this stuff? None of my normal online retail stores seem to carry it. http://www.expresscomposites.com/duratec1.html these guys carry the clear version but I’d like it in either black or orange, if possible.
You could put black pigment in it or buy a Gallon of black primer surfacer then follow with the clear. It will look like you painted and cleared it with auto 2k materials.
You could try Composites One for Duratec. Fiberlay has products similar to Duratec. It is called Orca Air Dry Coatings. They have both polyester and vinylester based products. Sanding, surfacing, and clear (I don’t know if they have colored top coats).
I called into expresscomposites.com today and they actually do have the black vinylester top coat (1902-045) in stock even though it’s not listed on their website. Not too cheap at $136 a gallon but the clear, which is listed as $95 on their website, is really $122 when you call in to place an order, so the other options aren’t great either.
Can the clear VE topcoats be thinned with a lacquer thinner, a la the PE primers?
Thanks for the suggestions!