The HobbyBoss 1/32 B24D Liberator.

[Guest]

Replace this all with roofing lead cut and hammered into shape, then pour the Liquid Gravity in the gaps left? A while ago we discovered that Liquid Gravity has only about half (IIRC) the specific gravity of lead, so even though you won’t be able to get lead into all the corners that you can get that, it will give you about twice the weight in the same space.

[Dave Ward]

Getting enough weight into the front is a definite challenge.

I wanted as much of the weight as far forward as possible.

I used two part Milliput to seal the front and end of a cavity on the starboard side, then I used Gator Grip to push in and around the dry Milliput to make sure there was a tight seal.
I then poured liquid gravity into the cavity and sealed that with superglue.
After that I used masking tape to create a wall into which I poured more liquid gravity in which was again sealed with superglue.

Then, after removing the tape, I did some test fitting to make sure nothing impeded the fit of the port fuselage and it was fine.

Next step was to put in another Milliput barrier which will enable me to pour more liquid gravity in once the fuselage is closed. A m other test fit, before the Milliput was dry and that job is done.

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Above you can see how it is left, for now. There will be some painting needed where the Milliput will be visible.

This photo below is how much LQ still need to be fitted, a full bottle plus what’s in the shot glass.

There is one large cavity which should take a fair bit over the nose wheel once the internal structure is fitted, but I will still have a lot more to get in. I have some ideas on that.
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Front of the inboard engine nacelles? Not as big as a lever arm as the nose, but quite a large diameter for washers/coins?
Dave

[BarryW]

I cannot do more with the ballast until the internal structure is cemented firmly in place. So I move on to look at how the ball turret fits.

First of all it is clear that I have to fit the ball turret before I close up the fuselage and also the pin that fixes the ball turret into the roof location is far too weak and may not survive the build.

So I cut off the pin and cut a pieces of 1.5mil copper tube to a length slightly longer than the pin I removed. I also drilled a 1.5mil hole to glue the pin to the turret assembly, the other end will fit into the attachment cemented to the roof.


Some superglue and that’s done


This is where I really appreciate the Wow Stick as the drilling of the hole is so much easier than doing it by hand. Even a Dremel is not as handy and easy to use as the Wow Stick. It’s perfect for models and I use it on every kit, multiple times.


Next I need to check the rear turret.

[Jim R]

Replacing the plastic pin is a neat, worthwhile modification. If it broke later in the build it would be a #@&+£#!!

[BarryW]

After lots of dry fitting and adjustment I have now been cementing the internal structure firmly into place. I am happy that the two fuselage sides will fit well together. There will be a fair bit of work on the long seams to do.

I have been working in sections using clamps and have now got towards the rear. I will leave it now for a day or two before fitting more ballast.



When I am happy with the ballast I will then fit the ball turret before cementing the sides together.

[Mickc1440]

It looks very impressive Barry

[scottie3158]

Looking good.

[BarryW]

Using cut down bombs and fuel tanks to hold ballast. I have fitted around 350grams of weight which, on top of the metal nose wheel leg, should be enough, once I have added another 30-40 grams in a void under the nose once the fuselage has been closed up. This compares to 300g recommend by HB. Why more? Because the 300g are indicated in the instructions to go in front of the instrument panel. Bearing in mind the glass nose, that would take up a lot more of the nose cavity making it even more noticeable through the transparency. There is no ideal solution to this but I decided to have over half the weight further back, as you can see which means more weight overall. I estimate that the amount of ballast in total, will be over 400g. If that turns out not to be enough I will have the front of the engine nacelles left and, as a last resort, I could shove more into the nose before attaching the nose transparency. I hope that won’t be necessary.

I did consider lead weights instead of liquid gravity as it is somewhat denser, meaning less material being needed. However the density difference would be offset by voids and packing it all in the nose would almost certainly bring it further forward making it more visible. For that reason I decided that there was nothing to be gained and went ahead as I have.

It doesn’t look great but will hardly notice when done.

I have also dry fitted the ball turret. You can see below how its only attachment will be the brass tube superglued into a location point set in the roof.

It is very precarious
Below you can see how the guns need to be lined up with some notches as it won’t swivel.

Once the fuselage halves are joined I will have a panel to thread under the guns while trying to get four long pins inside and locate into holes that I won’t be able to see. I suspect those pins will have to be cut off.


All in all it’s a very tricky operation to do.

[Jim R]

Well done with the weight, I reckon you've got as much in as possible. Certainly very fiddly to assemble and rather fragile.

[Andy the Sheep]

A very tricky ball turret engineering from HB, indeed.
I'm pretty sure you'll end up with a fabulous result, as always, Barry.
400 g of ballast... it's impressive! It's the equivalent of pasta for 4 helpings!:tongue-out3::hungry::upside:

[BarryW]

Another quick update.

I am using a mix of superglue and cement to bring the fuselage sides together.

I am working in sections using rubber bands as clamps don’t hold given the shape.

The two sides are under tension given the amount that’s being closed off inside it.

I will want to strengthen the bond when I come to treat the seams the question is how? My two options will be black filler c.a. or sprue goo. Does anyone here have a suggestion of which would be best or another way?

I still have to work the top backwards from behind the cockpit. I am doing a section and then leaving it to harden overnight before doing the next part.

[Jim R]

Sorry Barry, I can't offer any advice on strengthening the seam. It will be interesting to see what suggestions are made.
It's looking good and as Andrea says

I'm pretty sure you'll end up with a fabulous result, as always,

[Ian M]

Proper glue, plenty of it and get a good ooze going. Welded. No longer two parts but one.

[Tim Marlow]

I agree with Ian. Personally I’d use Contacta layered up to fill the gaps unless they are really large. It’s solvent with filler so will bond nicely with the airframe, and when properly dry will sand at least as well as the original plastic. Sprue goo might work, but will be more filler than solvent and will be inconsistent across such a large seam. CA is inflexible so will probably crack under handling unless you use the flexible stuff. It will not bond so well either because it only relies on surface mechanical interaction rather than the solvent welding you will get with Contacta.

[BarryW]

Well I ended up using a mix of sprue goo and black ca wherever appropriate.

The sprue goo was used in a few places where there was a visible gap. By using a thick sprue goo I was able to pack it into the gap. It is not a tidy process, a bit messy if fact , but it results in effectively welding the two fuselage halves together with plastic, providing a very strong join, as strong as the plastic itself. For those who don’t know, sprue goo is where you cut up small pieces of sprue and drop it into a bottle of cement, I use Mr S Cement, an extra thin type. The cement melts the plastic into a goo. It is very messy indeed to use which is why I don’t use it often.

I forgot to get a picture after applying the sprue goo and c.a., sorry.

After drying overnight I have done the ‘rough sanding’ to get most of the surplus sprue goo off for which my David Sander was very helpful.

Next I need to start smoothing it, using my sanding sponges, working down through the grits.

I expect that I will need to treat the joins further with my more usual materials, Mr Surfacer 500 and mostly Mr Dissolved Putty to totally eliminate any sign of the joins. A lot of rescribing will then be needed and some riveting too.

Here is how she looks now.


I will be doing this over several days, a little bit each day. Sanding and filling are my least favourite parts of modelling so I will be glad when it’s done.