Phenomenal P61 Black Widow project! - Page 5 - RC Groups
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Nov 20, 2005, 12:17 PM

P61C Black Widow series (#27)

Panel lines: This will be done in component form also due to the size of the aircraft. Attached are a few pics of the top surface of the wings with chartpak tape applied. A coulpe areas of caution here.

The wing tips present no real problems except that I have found that where you cut the tape at the root at the end of a panel line does cause issues. My recommendation is to cut the tape about a 1/2" longer - hanging over the edge of the root of the wing. Bend it down onto the root itself and then put small pieces of masking tape to hold it in place. I found during the process of applying the panel lines on the stab, that the solvents in the paint soften the adhesive on the back of the charting tape and this causes any stretch you have in the tape when you applied it to cause the tape to "creep". When you are finished painting you might very well find the edges of the tape, ON the wing are in fact, unpainted implying that the tape has effectively shrunk length wise. The masking tape stops this.

Another area of problem is and concave or convex curves that you have to apply the tape over. The LE is an example of convex, the transition between the tail boom fairings and the wing surface on the top of the wing is an example of concave. The tape, if streched during application will separate from the wing surface at these convex and concave areas resulting in gap in the panel line after spraying. The lesson is do not stretch the tape in concave and convex areas and this will eliminate any tape lifting.
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Nov 20, 2005, 12:37 PM

P61C Black Widow series (#28)

Spraying the panel lines.

The top surface of the wings were to get about 3 to 4 coats of paint over the panel lines. I mixed 4 oz of paint and let it induct.

Now, the primary item to consider here is the amount of paint you want to apply to the lines. Narrow strips of spray are what is required. I used my HVLP detail gun with the 1mm nozzel. I used the air control screw in the bottom of the gun to reduce the pressure at the nozzel to as low as I could and still spray paint - the input pressure was per the guns specs - 43psi however. The fluid control screw was almost all the way in cutting off most of the paint flow. Lastly, NO fan spray for this operation. This means closing the spray pattern screw all the way - you want a round spray pattern, minimal pressure and minimal paint flow. This setup makes the whole process a lot more manageable.

Once you have tested the pattern, start spraying over the panel lines. I started from one tip and worked to the other. 2 to 3 spray "swipes" per line from tip to tip.

Once you are done with one coat over all panel line tape, wait about 15 to 20 minutes for the solvents to flash off, then spray another coat, wait again, spray again etc. If you spray several coats in quick succession you will find the "shrinking" and possible detaching a larger issue because you have a lot of paint in a wet state softening the adhesive on the back of the tape.

The Klass Kote paint will stay uncured in the spray gun paint pot much longer than you would expect so put the gun aside for 15 to 20 and then spray each coat with the appropriate flash-off time. Once finished, let the paint cure.

Now, there are two methods related to cure time. Since you are going to want to clean out each channel of adhesive with MEK, you can wait the full 4 to 6 days before removing the tap, remove it and then clean the channels. The other way is to wait a day for teh paint to partially cure, remove teh tape and then wait an additional 4 to 5 days before cleaning - both methods work.

The last item is sanding. Again, two methods. Sand before you remove the tape. This does have a minor benefit in that you sand down to the tape. This leaves a very clean, crisp edge in the channel. If you choose the other method of letting the paint cure (short or long period), when you pull the tape off the wing without sanding first, you will create a very fine jagged edge along the channel. Most of this will be removed via sanding but in places, you will see the jagged edges. I use the pre-sanding method and then pull the tape.
Nov 20, 2005, 12:40 PM
Suspended Account
Thanks again for all the detail. It's all quite informative.
Nov 20, 2005, 05:06 PM

P61 - Pause!

Folks, not sure if you have read the preceeding posts but this is the first time I have built a model of this type using these techniques. I think it is going fairly well - the results look ok. If anyone sees any major mistakes I am making, please, provide input. I am open and willing to listen to the experts!

I also noted some time back in previous posts that I had drawn the hatches on the painted surfaces of the components. This includes hatches, the dive-brake surface features, the recognition lights on the bottom of the right wing and the landing lights also on the bottoms of both wings. I decided after looking at their location that these needed to be features added to the surfaces after I had painted all the panel lines. Many of these features were way too close to the panel lines and I felt that the overspray from the panel lines would adversely affect the hatches and other details. These will be added after the panel lines but before the rivets.
Nov 20, 2005, 05:13 PM

P61 - Pause!

OK, that now brings me to a question. Can anyone recommend a good method of creating surface flush rivets? I have heard of the 15W soldering iron with brass tube method but given this aircraft has thousands of rivets, I can see that taking weeks to complete. Same for the Dzus fasteners - well over a thousand of those.

I have also heard of the transfer type of rivets but I expect to weather this aircraft with Dave Platt methods using "washes" and paint thinner to get the weathering in the panel lines and rivet depressions. The transfer type does not work with the wash methods due to the copious amounts of paint thinner to be used on every surface during weathering.

Lastly, I have done some research with the Rosie Riveter method but this appears to be a fairly cumbersome, long winded approach with fixed pitch rivet templates. As with most riveted panels, the pitch varies to ensure you have rivets in the right place in each corner of each panel. I am not sure this is the best method either.

There are some raised rivets as well on the P61 and these will be applied to the surfaces using the tightbond/water mix via the Gaunt Industries oiler method.

Any ideas?
Nov 20, 2005, 05:22 PM

P61 - Pause!

Probably should identify the last post as a question - I'm also new to this forum so not sure this will work!
Nov 20, 2005, 07:34 PM
Registered User
were most of the rivets "counter sunk" ?? if so, I would suggest making a "strip" templete ( two or three rows 12" long) and transfer them that way ... make a "ring" imprint on the glass...
Nov 20, 2005, 08:19 PM

P61 - Pause!

Using what to make the imprint? What is the best tool?
Nov 21, 2005, 07:46 PM
Registered User
Tandy LeatherCraft made a smal indent tool.. it was hollow pint about .25" dia.. I think that would do your Dzus ones.. there is a "punch mark Tool that will do a small .15" dia imprint... I'll make a templete strip and take a pic of it for you this weekend.. its very simple once you get the layout..
Nov 21, 2005, 07:51 PM
Registered User
another suggestion... take aluminum tape.. cut it in 1/8" thick strips about 18" long... leave the backing on it... REMOVE the ink and ball point tube froma cheap Flair or bic pin... CAREFULLY press the open tip down enough to leave a deep depression but NOT thru the tape.... cut to panel line length as needed... remove the backing and press to your wing, fuse, tail, etc... prime and paint... the indentationns will look like counter sunk rivets... try a small section and see how much paint you DONT need to cover the rivets. adds weight, but not as much as you think... you can build up the inner edged with primer to show panel depth...
Nov 22, 2005, 12:37 AM

P61C Black Widow series (#29)

Panel lines continued:

Nothing much more than before - more chartpac, more spraying.

The pictures attached however show one of the things I mentioned earlier with the elevator. I had not taken pictures of the before stage of the simulated ribs but since I had only done one side of the elevator, this gives me a chance to show the setup.

You may note that all the corners of the masking tape are rounded - 1/4 round. I now use scalpels instead of modeling knives based on watching Dave P's DVD's. A good piece of advice especially when you get to this stage. What I found was a number of web-based suppliers that will sell handles (#3 handle) and #11 surgical blades - in boxes of 100 and individually wrapped - not as cheap as modeling #11's, but significantly sharper. Ideal for cutting masking take over the KlassKote undercoat. The rounded corners however, using the standard surgical handle, are a pain to do. The better solution I found is using the #11 surgical blade in the standard #11 exacto handle. Being round in cross section allows you to "roll" the blade between your fingers for the corners - very difficult to do with the surgical scalpel handle that is flat!!!

Anyway - a few pics of the elevator masking if they weren't clear before.
Nov 22, 2005, 12:47 AM

P61C Black Widow series (#30)

Nacelles and the louvers:

A confession here - a definite lack of planning!!! The P61C has a significant number of louvers behind the cowls. Two panels of them on either side of each nacelle - a total of 8 panels of louvers. But, I forgot to plan for them during the construction phase. What I should have done was vacuum form them from thin ABS, cut each one out and inset them into the nacelle sheeting itself. Oh well, what to do?

Well, I decided that I would simulate them instead using exactly the same method as the simulation of the ribs on the elevator, rudders and ailerons. The pictures below show the chartpac tape panel outlines with the masking tape in place to simulate the louvers. Once final painted, I will highlight them with an airbrush and weather them. Again, we'll see how they turn out.

Similar technique on the rudders as the elevator.
Nov 29, 2005, 11:43 AM

P61C Black Widow series (#31)

Ready for riveting!!

So, the panel lines are now all applied. The surfaces have been sanded. The gum/adesive from the chartpac tape however, has not been cleaned from the panel lines. The paint is still too fresh to apply MEK so I will wait to do this step until after the paint has really cured and the rivets are done.

The pictures below show the aircraft assembled and you can probably see all the lines drawn on the surfaces. These are the rivet lines and there is a lot of them. I have also redrawn the lines for the hatchs, lights, dive brakes etc because many of them were covered by the panel line paint. I have not however, applied the hatches and simulated formation and landing lights. MEK is a pretty powerful solvent and I am concerned that it will attack the adhesive of the hatch material and the ABS plastic to be used for the lights so I will wait to apply these until after the riveting is complete and the panel lines cleaned out.

There are two types of surface "riveting" that I will apply to the P61 - standard flush rivets and Dzus fasteners. The rivets will be made with a 3/32 OD - 1/16" ID brass tube mounted to the soldering iron. The Dzus fasteners will be made by a 1/8" OD - 3/32" ID brass tube with another straight piece of brass inserted into the tube its full width to simulate a slotted head screw.

I purchased a new adjustable soldering iron with a digital temperature readout. While the base unit itself allows for very accurate temperature adjustment that can be recorded for future use, the soldering iron itself was not easily changed to support the brass tubes. What I found I had to do was to cut successively smaller pieces of brass tube - the outer one fitting over the solder tip that happens to be one complete item that screws into the handle!!! It took about 5 pieces of brass tube until I got to the Dzus size I needed. 6 pieces for the rivet size I needed.

For both the Dzus and rivet tube, I found that about 525 to 550 degrees F produced a quick impression in the paint without the typical paint strings I have heard are normal for this type of riveting. The result was a clean impression with a requirement for very light sanding only.

So, onto riveting! Not sure how long this is going to take since I have not done this before. I'll come back when I am done and go on to show the remaining surface details (a couple of air scoops, wing tip lights, hatches, simulated formation/ID and landing lights etc).
Nov 30, 2005, 02:05 PM

P61C Black Widow series (#32) - SETBACK!!!

Well -------- SETBACK!!!!!!

It would appear that KlassKote is WAY too hard to effectively burn/melt rivets into! Bummer! The rivets that I did add using this method were more indentations rather than clean rings. The indentations were not even and their surface clarity depended on too many variables to get them to look good. The results were poor to say the least. I did not seem to matter what temperature, pressure or time on surface was used, the results were poor.

So, what to do????

I decided to experiment with the titebond/water glue mix with the Gaunt Industries hypo-25 oiler. I thinned the mix of titebond to water to about 60% water, 40% Titebond and applied rivets to a scrap piece of material. Once cured, and given the mix ratio of glue to water, I found that the rivets were flatter that the typical rounded style. I then proceeded to lightly sand the tops off the flattened rivets and achieved a slightly raised, but flat topped rivet string. So, would this work?

I called a few scale modelers and found out that this method is somewhat commonplace and the effect after weathering with washes results in small half-moon type surface features that do quite well at rivet simulation. Certainly not the desired look I was aiming for but adequate for this aircraft given the fact that it was already painted in KlassKote!!!

In further discussions with fellow modelers, it is apparent that if you want burnt/melted flush rivets, they should be done in the primer as this paint is much softer than a surface paint. Likewise for the panel lines.

So, this tells me that the method I have used on this aircraft was perhaps the wrong one due to the fact that most of the rivets on the P61 are flush. For raised rivets, this method works well.

Anyway, rivets have now been applied with Titebond to the fuse and the wing tips. I will need to re-work the surface of the stabilizer which was attempted with the soldering iron so that it is flat again for titebond rivets!!

Also, the Dzus fasteners were OK in places and poor in others using the soldering iron method. I have decided to fill some of these in, sand flat and then apply laser cut stick-on fasteners using monokote trim where they are really visible, like the cowls for example, and then paint over them. The remaining ones, which are not too bad, will stay as is and after painting and weathering should be ok. Most of these are on bottom surfaces and not readily visible.

Lesson learned!!!!
Nov 30, 2005, 09:38 PM
Scale Builder
SS2, did you sharpen the brass tube on the inside? I run an exacto knife around the inside perimeter and bring the tube down to a relatively sharp edge. I have not used KlassKote but I've never had trouble burning rivets in any type of paint. Must be some hard stuff!

PS - One other thing that I do that may make a difference. I hold the brass tube at an angle to the surface and use a rotational motion of the wrist to burn the circumference of the rivet. (hope that's understandable!) Sometimes if you try and hold the tube flat to the surface, so as to burn the entire rivet in one shot, you can overheat the paint and it will make for a ragged rivet or even remove the center of the rivet.

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