Graupner SAR Hertha Jeep

Started by Cashrc

5 updates 29 likes 19 comments
Cashrc Opening post

Graupner SAR Hertha Jeep

This is the second time I’ve built a Graupner Hertha Jeep. I built one a few years ago, and after a few runs converted it to brushless. She was my “go-to” boat for almost 2 years until an altercation between her and JPs Kitty II caused the loss of her superstructure. Well, JP had a brand new SAR kit in the box, untouched. We made a trade that involved, among other things, my Acapulco plus my old SAR boat for his kit and a couple of other items..it also involved me building a new, scratch built simplified superstructure for the old SAR. I’ve got that done, and am now in the process of building my new Hertha Jeep.😀

Now, I’m not going to do a step by step on this boat, as I covered a lot of that in the last build. I will, however, detail what I’m doing different because of what I learned from the last build. My old boat was built pretty box stock, with the exception of a hotter wind 400 sized long can motor. Unfortunately, if you drove the boat at full chat for a bit that motor would get pretty warm, and the stock motor was worse, so I swapped in a 1450 kv 28 mm outrunner. That motor on 6 cells gave the boat a good turn of speed, and never got much over ambient temperature…the boat was a reliable as anything I’d built after that. However, the radio tray/motor mount was designed for a can motor and strap down mount, and with all that in the way made it very difficult to install an outrunner..,.soooo…..

The first thing I did was to check the bottom keel for straightness. In my first boat the keel was tweaked near the aft edge, I had to cut out the offending piece and reglue it in place, with subsequent filling and sanding. The new keel was tweaked, not as dramatically as the first but more subtly, but the bend was longer. I had to cut, break, tweak and fill this one too. This, except for the instructions, was the only real flaw I found in the kit.
I decided to forgo most of the radio tray except for a couple of bottom former halves, I used those to make a base for my rudder servo mount. I also made up a bulkhead mount for the outrunner. Once everything was epoxied in, I did a test run. I got my alignment about spot on as this setup is much quieter than my old boat.
I did the cabin a little different too. The cabin pieces have “fold” lines molded in so you can crease the part and make it fit properly, like the front cabin windscreen. Now, the first time I built this boat I had a heck of a time getting the front screen assembled properly, and had to use a lot of filler. This time around I just changed up the assembly sequence and things went much better.
That’s where I’m at now, the cabin is mostly assembled and the rudder tube and propulsion parts are in place.I need to build the aft well deck and start getting ready for primer and paint.
Cash
Liked by Scratchbuilder and redpmg and
12 comments
  1. wingsounds13
    Leading Seaman
    Oh cheese! This group is almost as bad as I am. 😎

    Perhaps I see things a bit differently, but I always thought that the SAR was just a touch top heavy. Stable, but marginally so. This is one reason that I am really happy with my modified SAR with the lower superstructure. I do look forward to getting her in the water and seeing how close to overpowered I have gotten her. That certainly seems to be my trend. 😁

    J.P.
    Liked by RNinMunich

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Well deck and the start of (ugh) paint

Hi y’all. The well deck was the next thing I tackled. It’s a fairly simple structure, but one has to get it right as it supposed to slip into the aft opening in the deck. Also, it’s easier to get the rudder linkage mounted before it’s glued in place. There’s a bit of a sequence to this boat that in my mind, makes things easier, and it goes like this:
1. Internals. Motor, rudder tube and stuffing box.
2. External structures. Cabin and well deck.
3. Paint everything you can!!! Because of the multiple colors, and the fact that the deck and hull are one piece, having the hull and superstructure painted will make the next steps easier.
4. Paint frames and fittings.
5.install frames, windows and most fittings.
6.final install of radio components, rudder and shaft. Test.
7. Install well deck.
8. Fittings, rails and decals.
So, that’s the sequence in a nutshell. I’ve accomplished 1 and 2. The well deck was modified a bit, as the original gave you very little “wiggle room” to install and remove the drive battery. The original boat had the 6 cell nimh mounted on the hump aft of the stuffing tube slot in the hull. You had maybe an eighth inch of room above the battery. I shortened the well deck by 1/4 inch to make any battery install easier. Also, the aft part is supposed to match the curve of the floor, the original aft panel was much to stiff to make that without a lot of heat and mild cursing, so I made up a new part out of thinner plasticard. Worked like a champ!! I’m now in paint mode. I’ve also learned that I really hate white paint, as white and cream seem to go on wetter than any other colors, and runs more. Ask me how I know.🤣
So I think on the hull I need to do the bottom first, sides and top white, then the green panels, finally the orange rub rail. Gonna be….interesting. Might put me in a SARcophagus if Im not careful….😉
Cash
Liked by MouldBuilder and RNinMunich and

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Paint and windows

I took a week off so I decided to hunker down on the SAR. Got most of my paint done, save for the orange rub rail that goes around the perimeter of the hull. I also painted my window frames and installed the windows. Paint came bout good, windows decent. Tomorrow I’m going to finish up the rudder linkage and do some details to the cabin.
Cash
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I am ambivalent about painting..I loath glazing!!

I y’all. I have most of the paint work done, the mast is built, all linkages and motor/shaft installed…and most of the windows in place. Let’s talk about those windows. The SAR comes with laser cut plastic window frames and laser cut tinted windows. Pretty nifty!! Now, the first SAR I built I cheated, as you have too glue each window separately to the fram then install that assembly to the superstructure. I took a look at that and decided that it would be easier, and ultimately better looking, if I did single strips of clear sheet for each window row then install the painted frames later. That worked like a champ!! In retrospect, I should have done the same thing, but THIS time, I did the windows per the kit “instructions”. I prepainted the frames, used small dots of medium ca to glaze the frames, and installed. Well, I got thru it. All done except the upper cabin side windows. They look good in the pic, but if I were to grade my work on this it’d be a B-. Not my best work, passable at say 5 feet or so. I need to find a good glue that dries clear but has a good tack. Canopy glue works very well, that’s what I used for the skylight glazing as the window panels are inset to the roof. Ca works okay…but let me just say I’m glad the windows are tinted😂
Oh, the bollards are set up where you have to drill the deck to attach them. I just cut off the pins so I can glue them down, as I’m not drilling holes in the deck if I can help it!!
Anyway, got some more fiddly work to do, need to finish glazing, touch up any faux-pas I have, then finish up details and decals. She might splash this weekend if I keep my nose to the grindstone.
Cash
Liked by MouldBuilder and dave976 and
4 comments
  1. redpmg
    Commodore
    Looks pretty good Cash - probably the most difficult part of any build - even using perspex with both sides covered I still manage a few blotches ...............So join the club - think your idea on the original sounds great .
    Liked by Cashrc and Martin555
  2. CashrcGold
    Admiral
    Thanks Peter. Don’t know why I decided to do the windows the “stock” way, should have done it….wait for it….”Myyyyy Waaaayyyyy!!!”
    🤣🤣
    Liked by redpmg and Martin555

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Ninety eight percent done!!

Hi y’all. This morning I set out to finish as many details as possible, and finish the radio install,in the SAR. I’m happy to say I accomplished both with very little drama. The worst job was first, the upper rail on the superstructure. Now, I could have built up a jig, and soldered every part together, but I decided on a hybrid approach. I bent the main rail up, along with the 2 90 degree bends aft, and soldered up the very front post. I was able to then glue the rail on, and then attach the remainder of the posts from the inside out, and glue them to the superstructure and rail. I prepainted the brass stock, once everything was stable and set I touched up the paint. Came out pretty good! I then did decals, aft door and rails, and Velcro mounted the ESC and receiver. Except for the silver belts on the outside perimeter of the boat, and one or two other minor details, she’s done and ready to maiden. We’ll see how she runs and handles Sunday!!
Cash.
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Maiden run sucessful

Hi y’all. I maidened the SAR today and she came thru with shining colors!!! No video yet, next run I’ll get a vid. She andled well, turned on a dime just like the original boat. It seemed a little slower, even though I’m using the exact same motor I used in my original SAR, but I’m putting that down to the fact that I’m using a different prop. The kit comes with a 3 mm propshaft which utilizes a drive dog for the prop. I changed the shaft and tube to a 4 mm unit so I could have a greater range of props to choose from, plus 4mm threaded props are far more common than 3mm drive dog types. Anyway, I used a 3 blade of the same diameter as the original, but I think the pitch might be a wee bit less. In any case, it seemed just a little slower on a 6 cell nimh, but ran like I remembered on a lipo. Only untoward thing that happened was the loss of both port and starboard SAR decals, they came right off. They’re water slide decals, same ones that are still on my old hull, but I’m thinking that the first boat sat for a week or two before it splashed, versus the 2 days the new boat had before hitting water. In any case, I’m happy with her, I’ll just have to get some red Monokote trim and cut some out by hand, or find some red lettering in a close font and size. She took on no water at all, not a drop, even after running on the lake for at least an hour. I’m happy!!😀
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