tschmidt

My Feedback: (1)

Does anyone know what the producers of composite kits are using to make there epoxy fuselages white? It seems most of the composite fuselages now made come this way and I'd like to do the same when laying up my own.

Todd Schmidt

davidfee

It really depends on who is making the kit. In the old days, companies often used a thick polyester gelcoat, but that is really heavy and it cracks easily. On the upside, it gives the fuselage a "solid" feel that the unaware will really like. You still see this on some of the cheaper kits, as well as some kits from Multiplex.

Most of the time now, it's either a thin polyester "paint", often called "vorgelat" in Europe, or a catalyzed automotive finish. Either of these is far superior to the old polyester gelcoats. I've used other paint types... but for durability there's no match for a catalyzed paint system.

XJet

I use a little white pigment paste in with the first coat of resin -- works great. I've also been adding some silica to thicken the first resin coat so that it acts more like gelcoat. Once this first coat of resin (sans cloth) has gelled, then I start laying up the cloth and clear resin over the top.

Works a treat and lets me vacuum-bag the molds to get maximum strength/weight with good packing into corners and curves.

Deadstik

My Feedback: (8)

Todd,

As David said, it depends on who is making the kit... my kits are all PPG Epoxy primered.... the mold is polished, liquid mold release applied (not pva).... and then I simply paint the mold after masking.... Then layup the fuselage and then result is a pre-primed fuselage with virtually zero pinholes.... Then, all the modeler does is sand the seam line and prepare the fuse to paint.....

Dan

Carolina Custom Aircraft

tschmidt

My Feedback: (1)

Thanks guys for your input, Its greatly appreciated!

Todd Schmidt

JohnW

My Feedback: (6)

Can PPG urethane primer be used in place of the epoxy primer? I made a test part where I basically followed what Deadstick posted, but used PPG urethane primer, mainly because it is what I had laying around and I was practicing paint-in-mold. It seems as if I had a good bond between the primer and the first layer, but I don't know how it will hold up over time. Would I be better off with a epoxy primer or is the urethane OK? Thanks.

Deadstik

My Feedback: (8)

John,

I wish I was the one who knew the answer to that... I have not used any type of urethane products in my planes so I don't know. I do know that the PPG epoxy bonds very well to the glass/resin and basically becomes one when everything dries... couple of little things here though.. number one is that when you do paint the mold.. make certain that it is done in multiple light coats that have the completed depth BEFORE anything can dry.... that means.. don't put on a light coat, wait 2 hours and then do it again.. you will end up with the most horrible gator skin surface that I have ever seen.... I realize the epoxy is expensive.. but.. it works great.. and zero customer complaints.... so that's all I need.... not saying the urethane won't work... but.. try it in the field... and it may turn out that it is cheaper and just as good...

Dan

Carolina Custom Aircraft

Rikard Levenstam

Hi, I have made lot´s of fuselage´s and wings in epoxy. I have used pigmented epoxy, up to 20% by weight, but this only works with some types of epoxy. Latest Sukhoi project i used the fullscale T-35 white gelcoat. This is a thin sprayeable gelcoat that smells like xxxx.. This gave me a small extra weight and a very glossy finish.

If any question, send an email or have a look at my web page.. www.modellbyggeriet.se/sukhoi

/Rikard

daven

My Feedback: (1)

I have found that a relatively thin layer of white epoxy KlassKote coating in the molds does an extremely good job of filling all of your pin holes and still offers a great surface to paint over after the part is pulled.

Rikard Levenstam

I think the avantage og thin gelcoat is that part is ready when demoulding, if mould is in good condition... One problem is always releaser, PVA gives to bad surface finish i think. I use only wax, and that gives nice finish. I get best release if mould is water sanded with eg. 400 paper, then the wax seems to grab in the sanded surface and gives good finish and good release. Next problem then is that the gelcoat could go like water on a waxed car.. but this can be fixed to..

/Rikard

chelapa

Rikard.. how can it be fixed?

tschmidt

My Feedback: (1)

Dave,

What release agent do you use in the molds before spraying the white epoxy?


Todd

Deadstik

My Feedback: (8)

Todd,

Sorry for the delay, had to go out of town... will get you the chemical list out tomorrow.

Dan

giantflier

Could you also tell how to paint in molds?
Also what is the best way to join two parts of fuselage?

daven

My Feedback: (1)

I have used wax only (dolphin wax) and also wax with PVA sprayed over that. You can get an extremely smooth coat of PVA down if you take your time and mist it on VERY lightly and use several coats. The only time I get a poor finish with PVA is when I try to hurry up and try to flow it like paint. The only problem with using PVA is that you can not tape off or stencil to it without it pealing off.

Here is a picture of a recent plane built and painted in the mold for me by Bruce DeCastle of www.bigbruceracing.com

Dave

giantflier

I took a look at "stits" and unfortunatelly got nothing about painting in molds...

tschmidt

My Feedback: (1)

Finally came up with a white one. Thanks Dan (deadstick) for your help and information. The PPG epoxy primer is easy and works well.

Todd Schmidt

Deadstik

My Feedback: (8)

Todd,

That fuselage looks really nice. You trying to make me build a 2 meter bird?????? Glad you had a good turnout on the fuselage.


Dan

Carolina Custom Aircraft