help please.....Duratec Sandable Primer for mould surface.

[wind_apparent]

I am almost done with my male mould forms for my Sailpowered hydrofoil project and I want to coat them with Duratec sandable primer as my tool finish. I have never used this stuff before and have a couple of questions: Is this brush or rollable or do I have to shoot it? Are there any issues with humidity (some of these coatings have bonding issues even with low humidity levels). And Do I have to buff it all the way to gloss or would sanding to 400 or 600 do the job? Thanks.

31987

31988

[ondarvr]

I thought I answered this earlier, but it's not here now ??

Brush or roller? sort of, but you would need put on too many coats to make it worth it, you'll sand through trying to get it level. Spraying is the only good method on something that size.

Humidity will slow the cure, but it really shouldn't create a big problem.


You don't need to buff it out, but it sands and buffs fairly easy, so after using 600 grit you should be able to buff out about 95% of the scratches.

[wind_apparent]

I thought I answered this earlier, but it's not here now ??

Brush or roller? sort of, but you would need on to0 put too many coats to make it worth it, you'll sand through trying get it level. Spraying is the only good method on something that size.

Humidity will slow the cure, but it really shouldn't create a big problem.


You don't need to buff it out, but it sands and buffs fairly easy, so after using 600 grit you should be able to buff out about 95% of the scrathes.

Thanks, looks like I'll take it over to my buddies shop and shoot it, then sand it to 600 and call it good. How many coats is standard?

[ondarvr]

No standard amount, you just need to put on enough coats so you don't sand through the high spots.

[Landlubber]

Keep sanding till the surface is as you require without going through the Duratec, when you do go through, simply respraw and then use a guide coat of say black dust spray, sand that off and the surface is prepared.

[wind_apparent]

Keep sanding till the surface is as you require without going through the Duratec, when you do go through, simply respraw and then use a guide coat of say black dust spray, sand that off and the surface is prepared.

Can I color the 1st or second coat with something and use that as a guide coat? I don't want to sand through because my painter lives about 45mins away. (I only want to move these things once, the hull tool is 260 pounds and I need to borrow a trailer to do it.) What could I color it with?

[In Theory]

I have used polyester tint (pigment) to modify gray to an almost black for use as a guide during sanding later.

[ondarvr]

For what you need to do almost any type of pigment or gel coat will work to slightly change the color.

[gonzo]

With most things in life, you pay now or you pay later. If you don't buff the molds you will buff the hulls. A mold with a rough surface may cause problems to remove parts.

[ABBOTTCRAFT]

I use Duratec Surfacing Primer on plugs as it produces a harder, glossier finish than sanding primer.. Sanding Primer is OK to buildup a surface but you will find that a final coat of Surfacing Primer will produce a better surface...

[wind_apparent]

I use Duratec Surfacing Primer on plugs as it produces a harder, glossier finish than sanding primer.. Sanding Primer is OK to buildup a surface but you will find that a final coat of Surfacing Primer will produce a better surface...

I'm talking about Sandable surfaceing primer, is there something different?

[ABBOTTCRAFT]

here's a list of the primers for Hawkeye Industries website.. You will still need to sand the surfacing primer with fine paper & buff, it has the hardest surface of the primers listed below & will withstand more heat...


Sealing, Fairing, Priming and Surfacing Application: Plugs, Patterns and Models


**Duratec Polyester Base Primer (707-051 Tan)

**Duratec Polyester Surfacing Primer (702-003 Black, 707-002 Gray, 714-002 White)

**Duratec Polyester EZ Sanding Primer (702-060 Black, 707-060 Gray, 714-060 White)

[Doug Lord]

Ondarvr, is something like duratec ok on epoxy resin?

[wind_apparent]

here's a list of the primers for Hawkeye


**Duratec Polyester Surfacing Primer (702-003 Black, 707-002 Gray, 714-002 White)



Yup, that's the one I was going to use.....whats a good sanding schedule for this product? any tricks I should know about? I'm shooting it right onto freshly sanded 6oz glass, do I need a sealer or basecoat or anything?

[ABBOTTCRAFT]

I have used it without a sealer & had no issues..

[ondarvr]

Ondarvr, is something like duratec ok on epoxy resin?


For the normal polyester products no, but they make many specialty products and may have a product that might be better.

[wind_apparent]

Ondarvr, is something like duratec ok on epoxy resin?

They spray Duratec over fiberglass/epoxy as a tool serface sometimes, the guys I have been talking to about it (Carbon racecar parts shop) do it all the time. They say just make sure to scuff up the surface really well with 80grit before you shoot. I don't know about putting it right over a solid epoxy surface. I know that poly doesn't have the best bond with epoxy, but it seems to be working for the pro's, so I'm going to trust them on this.

[wind_apparent]

I just got off the phone with Denis over at Revchem, he said that as long as the tool doesn't get to hot, Duratec Surface primer would work alright, but it would be better to shoot it with Duratec vinalester primer, sand that, then shoot it with Duratech high gloss coating and wetsand till smooth.

[ondarvr]

VE's do bond better and I recommend the their VE product to many of my customers. I just hate to make claims on bonding polyester or VE to epoxy, because while it does sort of stick, its not near the bond you get when using one of these two products over a substrate of similar chemistry.

[Doug Lord]

wa, you need to start final sanding over ONE material-whatever it is-at 80 grit(at the finest)-and not go thru to another material of a different density. If you go thru and keep sanding you will be creating waves. From pictures on your site it appears you may have already done that with coarser grit-and if so-it will be almost impossible to correct. Ideally, you would have used a material that when finished with 36 grit would have been one uniform color.

[wind_apparent]

wa, you need to start final sanding over ONE material-whatever it is-at 80 grit(at the finest)-and not go thru to another material of a different density. If you go thru and keep sanding you will be creating waves. From pictures on your site it appears you may have already done that with coarser grit-and if so-it will be almost impossible to correct. Ideally, you would have used a material that when finished with 36 grit would have been one uniform color.

My tool is sanded to 80 grit, and the surface is one material (fiberglass), this is a prototype tool (read "one or two off), not a production mould (its to help me learn the process before I try a real plug and mould), the foam goes on the outside of the first skin and gets faired before the second carbon skin. the hull will spend a most of its time out of water (read "foiler that actually flies). The guy helping me learn owns a carbon shop http://ebscarbon.com/about_ebscarbon.asp, he seems to think my tooling is fine, so get over yourself)..... please go away doug:o :o :o :o :o stay out of my threads, please stop poisoning the name of all that foils, you turn people off before they can even get turned on. The only revolution I see is the one against You.

[wind_apparent]

For those wondering about epoxy/duratec bond issues, I just recieved this e-mail from Bill Beaver.

"I did use epoxy resin on my mold and microlight to fair it up. Then shot the thing with Duritec Easy Sanding Primer. I haven't had any problem with duritek sticking to epoxy to create a mold surface. Its certainly good enough to pull a dozen parts out of and probably a couple dozen parts.

Cheers,
Bill"

So if your planning to build a simple mould that you want to pull a small run of parts off of, Duratec over epoxy should be fine.