I have decided, while waiting to get to the AWM in Canberra, to enter the group build. As I've left myself a lot less time, I decided on a reasonably fast build; a Mk. II supply tank based on Airfix's Mk. I/II/III. In spite of the build advice on this site (thanks David), I think the appearance of the kit will be improved by removing some of the rivets and at least giving it a semblance of girdermakers pitch. Incredible as it may seem, there are areas where there are too few rivets. I'll be adding a scratch-built drive sprocket and idler to position the tracks a bit better. And as far as the tracks go, I'll give scratch-building my own a shot. Like everyone else, I don't like the standard Airfix tracks; their only advantage is that they look better than no tracks at all. Hopefully, I will finish this by March 31st.
As promised, WIP shots of the Mk. II supply tank. The rivets have been made from stretched sprue, the sheeted over sponson area with 20 thou styrene, the angle iron on top of the sponsons is made from 5 thou styrene, and the cut away areas at each end of the horns are to allow fitting of idlers, sprockets, and rollers on the right front horn.
All that remains to be done is scratch building tracks with a thrown track on the right horn, cleaning and detailing the right sponson door to display it open, and building stores boxes (and stores) for the roof and rear of the tank. And somehow making or adapting decals (possibly the most troublesome part).
P.S.: The cab roof hatch: I haven't forgotten it, it really did exist on this Mk. II supply tank. The silencer was also fitted.
Just a few more shots showing the battle damage and internal framework before the rollers, idler, and sprockets are installed. Also the port sponson needs a figure adapting to fill the doorway and conceal the lack of interior detail! And then the hard work starts; making my own tracks!!
BTW, the battle damage is as accurate as I can make it in Braille scale, thanks to the great photos I found on some website or other about WWI tanks....
Nice work there, Mark! You say you used stretched sprue for the new rivets (which, BTW, look really good) - did you cut thin slivers off and glue them directly on the surface, or did you drill small holes where you wanted them and then insert a short length with a bit sticking out?
Thanks Roger. For the rivets, I used a modified method that you posted much earlier using stretched sprue. First, I drilled holes for the rivets right through the model part. Next, I heat stretched the sprue fairly thin and then cut it in the middle of the stretched area. Now comes the tricky bit; you take the end of the stretched sprue and move it slowly in towards the base of the flame. When it gets close enough, the heat domes the end of the sprue just like a real rivet. Cut it off with a 1 - 1.5 cm (3/8 - 5/8 in.) tail. Repeat as often as eyesight allows. Voilą! Rivets!! When the cross section of the sprue starts to thicken, use another stretched piece.
To use the rivets, place a rivet in the hole till the tail pokes through the other end and apply cement sparingly to the tail. Capillary action draws the cement up and the rivet is done. Where the hole cannot be drilled through the part (e.g. at the rear corner of the sponson and the top edge of the cab), drill as deep as possible and make the tail of the rivet shorter than the hole. To apply cement to these rivets, I dipped an Exacto blade in the cement and very carefully touched the edge of the blade to the point where the rivet and the part touch.
The only hard part is getting the sprue to dome consistently. Too long near the flame (and too long comes on extremely fast) and the rivet turns from 1:72 scale to 1:32 scale! I found the best sprue seemed to come from Tamiya kits and it has to have a round cross section. Sprue retains its shape even when stretched to hair thickness.
Actually, this method would probably work just as well for the larger scales. Just don't stretch the sprue quite as thin.
P.S.: If your eyes were good before trying to make these, they certainly won't be afterwards!
Thanks for the details, Mark! It sounds like you have a lot more patience than I have, I don't think I could manage it for too long. I did actually have a go at doing the drill-n-sprue method (the first part of what you did) and that was bad enough without doing the flame part (which would definitely be necessary, as just popping stretched sprue in the holes makes for strange loking rivets; they really do need 'doming'). I think I'll have a go for sections with not too many rivets, though...
I think I'll have a go for sections with not too many rivets, though...
I agree with you completely. I decided not to re-rivet the sides of the tank to give it girdermakers pitch, mainly because it would take so long. As everyone knows, those tanks had quite a few rivets!
Once I get the rollers and idlers finished and installed, I'll post a few more shots.
That would be great, Mark. On the subject of having to make lots of rivets, I made a simple jig which incorporates a home-made punch-&-die which is great for making long rows of rivets in an absolutely straight line, evenly spaced, but it's only any use for making such rows near the edges of thin styrene plates. Its specific use is for making the riveted angle-iron that goes around the border of the track frames on all early British AFVs. I also made another jig for punching rivets in curved arcs for detailing the ends of the track frames. Next week I hope to borrow a digital camera, so I'll post some photos. Your method is great for detailing other sections, so I'll have to give it a go (no matter how mad I go in the process...).
Roger Todd wrote: That would be great, Mark. On the subject of having to make lots of rivets, I made a simple jig which incorporates a home-made punch-&-die which is great for making long rows of rivets in an absolutely straight line, evenly spaced, but it's only any use for making such rows near the edges of thin styrene plates. Its specific use is for making the riveted angle-iron that goes around the border of the track frames on all early British AFVs. I also made another jig for punching rivets in curved arcs for detailing the ends of the track frames. Next week I hope to borrow a digital camera, so I'll post some photos. Your method is great for detailing other sections, so I'll have to give it a go (no matter how mad I go in the process...).
so you have finally started to work on your group build?
Well, I've got a minor project which I will use as my Group Build entry (I'm modifying Airfix's venerable Mark I to make it more accurate), and also my scratchbuilding projects, which will be in no way ready for the Group Build deadline, whenever it is!
BTW, I tried Mark's technique of making rivets last night on a trial section of track frame I made for the purpose a while back, and it works a treat! I don't use stretched sprue, though, as some time ago I bought several packs of 10-thou styrene rod; as they are a consistent thickness and round in section, one can get excellent, fairly consistent results (the rod is a very shiny brownish-red for some reason, and I suspect it's what Gabriele Zenoni used for his Mark I master, as the results are identical: http://henk.fox3000.com/gzenoni/mk1.jpg).
So, many thanks, Mark, for sharing your technique here, it has really solved a bit of a headache I was having about how to proceed!
Glad to hear it worked for someone else. Aren't those rivets fun to make?
Where did you get the 10 thou rod from? It sounds like the perfect solution to getting a consistent thickness. As far as colour goes, the brownish red would be good for visibility against the (usually) green or grey parts.
It's great fun! Probably not as bad as it could have been as I'd already drilled all the holes ages ago, so that eliminated the first stage...
Now, trying to get 10-thou was a pain at first. I live in London and there's an excellent model supplies store called 4D, which carries a wide range of styrene sheet and rod, but even they had none. A search on the internet turned up only one supplier:
So I used them and had no problems whatsoever. I ordered 4 packs, seeing as they're cheap enough. And yes, you're right, the colour difference is very helpful.
Great tip, Roger! The local stockists didn't have any so I ordered 4 packs of rod online. Less than a week later, it arrived and works really well. The advantage it has, as you pointed out, is that the cross section is constant.
A number 80 drill bit, some 10 thou rod, and now I can rivet all day long....