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HubertB

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    What is on your bench right now ? Share a picture :)

    in Modelling Discussion

    Posted

    12 hours ago, GusMac said:

    Great explanation Hubert thanks.

    Hadn't even thought of what grain there is in silk being enough to cause moire patterns. Brings back bad memories of physics lab experiments 30+ years ago!

    It’s a long time since the silk in so-called silk-screens has been replaced by nylon or polyester, but the moire problem still shows up, believe me ;)

    This said, moire effects in silk fabrics were sometimes sought after, and amplified by minute variations of the silk filament diameter.

    Hubert

    • Like 5

    What is on your bench right now ? Share a picture :)

    in Modelling Discussion

    Posted

    1 hour ago, Bill_S said:

    Enlighten me, Hubert. Why are many of the 3D printed parts designed at an angle?

    3D printers all work in the same way: they add layer after layer of the part being printed. When you have straight lines on this part, either vertical or horizontal ones, the risk is great to have visible steps between layers, if the printer is not perfectly laid flat, or if it "wobbles" by the tiniest fraction of a mm on the Z (vertical) axis.

    Setting the part at an angle is a way to avoid steps and having the layers more visible as the human eye unconsciously sees "lines" along the part's main axes and spot discrepancies along these.

    We have the same approach when tensioning silk screens: if the weft and wave of the fabric are set at right angles to the screen frame, you end up with a moire effect of the straight lines being printed, sometimes to the point that the fine straight lines look wavy. Hence the fabrics are most of the time set on the screen frames at a 22.5° angle.

    It is also a way, when you have an overhang of the layer being printed above the one under it, to avoid having to add too many supports for this overhang. The layer is "connected" to the layer underneath by the angle of the part.

    Finally, for this part, this was also a way to have the part fit within the limited dimensions of my printer.

    By the way, the parts are designed along "normal" X,Y,Z axes. You set them at an angle on the slicing software that preprocesses the part to be printed into the hundreds of successive layers (in the case of the Mystery Ship fuselage, there are about 2900 layers). This is also when you add the supports. This is an art in itself, even though the software does the support design and placement automatically most of the time. I had the supports wrong on the left fuselage half, and stopped the printing about halfway, with an undeterminate "blob" :banned:. A printing for a part this size on my DLP printer takes about 13 hours, for your information.

    I hope that my explanations are clear. If not, just ask.

    Hubert

     

    • Like 3
    • Thanks 2

    AK Extreme Metals v Alclad

    in Modelling Discussion

    Posted

    40 minutes ago, DocRob said:

     

    @ Hubert, just for clarification, are you referring to AK's acrylic black primer or the dedicated Extreme Metal black base?
    After much praise, I tried Mr. Levelling and had the results you described, with the acrylic base and some AK acrylic colours as well as some Lifecolour's.
    I made my peace with the stuff, using it to thin Tamiya acrylics, where it works perfectly good.

    AK' Extreme Metal flat base is another breed and they recommend it as a base for their high polished shades like chrome and polished aluminum and that's where I used it without problems.

    Cheers Rob

    I wish I could post a picture of it, but I just threw the stuff away in disgust after my experience. I have woved since not to touch anything "AK primer" since. But yes, this is the acrylic base IIRC.

    Hubert

    • Like 3

    AK Extreme Metals v Alclad

    in Modelling Discussion

    Posted

    32 minutes ago, GusMac said:

    Thanks guys.

    I tend to use Mr Levelling as my go to thinner for everything so that should be okay. I've only used the Extreme metals over black Mr Surfacer 1500 so far and I like the results but I suppose for a shinier result a gloss base might be better.

    My attempt at humour obviously misled you: AK black primer + Mr Levelling Thinner = tar-like goo in the airbrush  within 5 ‘ . You are then good for a good afternoon cleaning, with all the hard stuff you can find, including acetone :(

    Hubert

    • Like 4

    Size matters... Just for fun, what is the biggest box in your stash ?

    in General Discussion

    Posted

    Mark31’s post in Ernie’s F-105 build prompted this interrogation: what is the biggest box in your stash ?

    The size of the box does not necessarily correlates with the size of the content, btw. Some manufacturers have an uncanny capacity to have big boxes for average-sized kits. Take for instance Revell’s Hunter kit : the box uses a lot of acres, for an aircraft that is not so big in the end, if certainly not diminutive.

    I’ll bite for my question : Trumpeter’s Titanic is easily the biggest box in my stash, and it’s full ! AMT’s LZ-129 kit (in 1/225) is close on its heels, but this one is rather full of air :) .

    And to conclude, 3 of my biggest boxes are ship kits.

    Hubert

    • Like 5

    AK Extreme Metals v Alclad

    in Modelling Discussion

    Posted

    If you use AK’S black base, be aware that it dilutes and cleans with water.

    On the other hand, if you like spending an afternoon - after all we have plenty of time in these lockdown times - cleaning goo in the tiniest spots of an airbrush, you can use my goto thinner for airbrushing, i.e. Mr Levelling Thinner. Trust me when I say it’s a 100% result ;) ...

    I have yet to try the MRP metal colors.

    Hubert

    • Like 3
    • Thanks 1

    What is on your bench right now ? Share a picture :)

    in Modelling Discussion

    Posted

    Feeling pretty smug about an experiment I just ran with my EPAX 3D printer. I taxed its capacities to the limit, but it worked, with an incredibly smooth surface. The fin tip is broken because of my clumsy attempt to straighten it, but that’s a nothing. One area on the fuse got pretty thin, but I think it’s more to do with my design. 
    And finally the transparent blue color is just the resin I had available. Some grey one is on its way. 
     

    i-cxw3grn-600x450.jpg i-ZV3xPqH-338x450.jpg i-9sX6T4T-600x450.jpg


    That means I can resume a stalled project that was sitting on my (virtual, as it was in the computer only) SOD ...

    Hubert

     

    • Like 9
    • Thanks 1

    Zoukei-Mura P51D Mustang SWS No 4.

    in LSM 1/35 and Larger Work In Progress

    Posted

    15 minutes ago, Kaireckstadt said:

    Sounds interesting! There are a lot of beautiful liveries available. I personally like the Tuskegee Airman Mustangs with their red tails. Do you know if the wings of NMF-finished Mustangs were painted? I read that the wings of the Mustang were puttied. Do you also plan to do it? 

    Now, THIS is the MEGA can-o-worms question :rofl:!

    IIRC the Mustang wings were puttied, and then painted. But the putty and paint were not applied on the whole wing (guns/ammo servicing panels are an obvious area where putty was useless, for instance). The idea was to maintain a smooth airflow and delay the onset of turbulences on the upper wing skin. Ergo the wings were puttied from roughly the LE to the main spar.

    Then there is the issue of in-service maintenance, wear and tear, etc. which made keeping a smooth wing for the laminar flow even more complicated ...

    Btw, whilst the P-51 laminar flow wing was an important factor in its performance, I remember reading that the radiator design and exhaust were a greater factor in its speed achievement.

    And to conclude, very nice work, Phil :thumbsup2: !

    Hubert

    • Like 6

    Gloss coat before decal matt coat after to seal it in?

    in Hints and Tips

    Posted

    You’ll get a thinner, and more consistent layer with a spray can. Hence my suggestion of Future for a brush application (it’s also dirt cheap compared to hobby paints)

    If you use a spray can, some tips: 

    1) put it in a warm water container beforehand, and any time you pause. You’ll thus get a more consistent result across its use. The progressive decompression of the propelling gas will make the can colder and colder, and the pressure will fall faster, with risk of splutter in the end.

    2) start spraying before the model, and stop after the model. This will ensure you do not have paint build-up on the kit when starting spraying.

    Hubert

    • Like 2
    • Thanks 1

    Gloss coat before decal matt coat after to seal it in?

    in Hints and Tips

    Posted

     

    Hi Pintar,

    The process you describe sounds sound.

    "Silvering" happens when the decal carrier film shows though around the decal motif. This happens when setting decals on a matte surface, because the surface is slightly grainy (at a microscopic level), and microscopic air bubbles remain trapped between the decal film and the model surface.

    By spraying gloss varnish, you produce a smooth surface that is less likely to have these micro-irregularities, and the carrier film will thus optically disappear.

    Now, to make things even surer, I would advise you trim away the carrier film by cutting the decal as close as possible to the actual motif.

    When everything is settled, spraying a coat a matte varnish is the right thing to do if you want a matt finish for your kit.

    Rob's recommendations are all sound, especially testing. We use a lot chemicals in our kits, and very often overlook the possible interactions between some and others, like paints.

    Finally, I have read that you have only access to Revell varnishes. I confess it's a long time I have used these. Plus you do not say if you spray (my assumption) or brush the varnish.

    If you can there are some worthy alternatives to go hunting for :

    -Tamiya X-22 gloss varnish or TS-13 in a rattle can,

    - Future (according to countries it can also be called Pledge or Klear) is a floor protection product. It is astounding in its results when applied to kits. And it works great applied with a brush.

    - You can also look for in art stores for oil painting varnishes. A number of my buddies use them with success.

    - Finally, there are plenty of other "brews" for varnishing kits, but I confess I have no knowledge of how most work.

    HTH

    Hubert

    • Like 2
    • Thanks 1

    EF-105F Thunderchief YGBSM

    in LSM 1/35 and Larger Work In Progress

    Posted

    No, Ernie, it was definitely silver paint. Very much like English « Speed Silver ».

    In the early 60s, Look-Alike was put in place to harmonise to the same standard all the F-105s. As operations in Europe had shown that the ‘chiefs were susceptible to weather corrosion (have you seen the rain when it’s falling on Bitburg :rolleyes: ? ), it was decided to paint the F-105s in silver. Then, when deployed in Vietnam, they were camouflaged in the SE-Asia scheme.

    Thus, at one time between 1964 and 1967, you had NMF, silver-paint, and camoed F-105s, although the NMF birds were disappearing fast... There were even some « D » in NMF in the early Vietnam deployments. But, if European rain was bad, imagine what it was like in Thailand or Vietnam ...

    My assumption is that, besides the prototypes, the « F » were delivered in silver paint, given the timing.

    Hubert

    • Like 5
    • Thanks 2
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