8178

My Feedback: (17)

Interesting, they are both acrylic lacquer so they should be compatible. I do wet sand between coats though. It is important that all paint layers are fuel proof and that’s why I used acrylic lacquer primer.

doxilia

My Feedback: (3)

Mitch,

The polycyclic is a water based "resin". The DC grey primer is a DC lacquer compatible polyester resin based filler primer (note: not LK compatible). It is typically a good idea to first use a primer sealer as the first coat in order to provide a base for the filler primer. DC also makes a primer sealer and polyester doesn't like too many other chemicals so I can see the polycrilic and polyester not getting along...

With polycrilic I would use one of two approaches: 1) waterborne all the way to the urethane clear or 2) three layers of primer if using LK. This last is rather specific about not being compatible with other products other than its own brand. As Mike mentioned, the LK colors also don't provide color match with MK unless you use LK primer underneath. So basically you first have to seal the glass with the primer sealer, then use the primer filler to obtain a uniform surface (along with body filler) wet sanding between coats. Finally, before the LK color coats, you shoot a uniform layer of LK white primer to seal the polyester of the primer filler. This will prevent the paint flaking which seems like rejection between layers.

I have found other primers including inexpensive white Krylon primer that will take LK well but I haven't been too impressed with LK so I used other brand rattle can paints on the Tipo I painted recently. I even mixed lacquer and enamel on the same fuse with the appropriate primer in between. So long as incompatible chemicals don't "see" each other and can't interact chemically one can get away with things which one really shouldn't do. On the job I did, my problems arose with a very poor quality clear I used from DC which yellowed as it cured. I had to sand it all off and go back to painting in between trim tape that was already applied... It was a blast!

With that I learned my lesson with clears; nothing but the best - acrylic urethane. I used an amazing product called SprayMax - highly recommended! Urethane is very tolerant of other chemicals and can be applied over just about anything. At ~$23 a can its not cheap but all it took was one can for the fuse and vertical and wing center section - in two costs. Well, worth the price.

David.

doxilia

My Feedback: (3)

Mike,

that was my initial thought too. I assumed that since LK is also acrylic lacquer that it should apply and be very similar in formulation to DC perfect match paint - it turns out that they're rather different. DC PM lacquer applies in a "dusty" fashion and dries to a powdery consistency. It doesn't have much gloss to it. LK on the other hand seems to have some sort of "clear coat" type chemical added to the lacquer formulation and leaves a slightly glossy or shiny finish once dry which of course you know. I've been trying to figure out exactly what this "clear" additive is that is in LK but it is hard to tell from its forumation sheet. There don't seem to be any obvious differences in basic chemical contents between the DC and LK. The two do however dry very differently.

One thing is for sure, DC PM acrylic lacquer is not fuel proof. It is intended to be covered with a clear coat but DC clear is not fuel proof either. Not to the degree that we might want them to be. DC produces at least two types of rattle can clear; one is lacquer based while the other is enamel based. I tried the latter assuming it would be a better nitro proof product but the results were less than desirable - at least in terms of finish. As mentioned above, the product yellows considerably as it cures. The lacquer I am told from my automotive store doesn't yellow "as much" but it costs about 30% than the enamel so I didn't try it.

After the poor results using the DC acrylic enamel clear, I decided to stick to SprayMax acrylic urethane and can't say enough good things about it. It applies in a "compressor like" fashion. The action out of the gun feels "pumped" as opposed to "sprayed". It also lays down a very nice pattern and it is quite resistant to runs if applied per directions. It cures to a buttery like feel to the touch and after polishing it has a silk like surface - the hand just slips off the surface.

David.

SuperViking

My Feedback: (4)

I know this is old but when installed the trailing edge before sheeting the wings how did you taper it to follow the airfoil without harming the cores, or was it already pre-shaped? ...............................thanks

jmb52760

It's not already pre-shaped. It was a stock piece of wood. I shaped it with an Xacto Razor plane until very close to the ideal shape and then sanded it the last bit. I used white glue and you can feel in the razor plane when you are getting close to the core. It's really easy to feel and hear when you hit the core with the sanding block. So you just tilt the tool to match the shape.

doxilia

My Feedback: (3)

Some masking tape along the TE of the core also helps to avoid an inadvertent cut or sanding of the core.

David

SuperViking

My Feedback: (4)

Thanks for the info.

hamza_b

I recently ordered the kit and right now going through the building of the elevator. One thing i dont understand is that the V-shaped spars are S14 S13 and S12. i too ordered the kit from eureka but i dont see S12 rest are there...is S12 the same as S13.

please guide. Thanks