S.M. U-1 (a new RC project)

[Das Boot]

Is that really you? I’ve never seen you before. I thought you were a blonde blue-eyed German. I’m third generation German.

[DrSchmidt]

After allot of painting, grindig and polishing. I finally have a good master. Now it's time to set it up for making a mold. The master is screwed onto a plane, stiff, and level board.





Then I set up the parting plane and filled the gap between board an boat with camdle wax...

[JHapprich]

Ah, i see.thank you!

[DrSchmidt]

I used MIPA 2K Epoxy Primer -> rattle can

https://www.amazon.de/dp/B004AHH17O?psc=1&ref=ppx_yo2ov_dt_b_product_details

[JHapprich]

Did you spray the mixed filler with the compressor? What brand did you use!

Nice and clean work!

[He Who Shall Not Be Named]

So! Lex Luthor is one of us. (squeal of joy!).

[DrSchmidt]

Time for some 2K epoxy filler....nasty but good. Went well. When the filler is cured it's 600 grid wet sanding and then'we'll see. I guess I'll need some more bondo here and there, but as the master determines how good the grp hulls will be, it's worth the effort.

[DrSchmidt]

Lots of progress...well, invisible one, as filling and grinding doesn't change the shape of the boat much, bit it will be visible, when the filler is applied. And that's what 's going to happen next. To be able to apply the filler/primer, I have to suspend the boat somehow. as there is no obvious attachment pint, I had to create it myself. So I glued two M4 threaded insets into the keel and made a suspension frame with a counter weight. Now the boat hangs straight and freely accessible under the ceiling of the work shop. Next I will degrease it once more with "Silikonentferner" (I guess something like the soft solvent David uses). And then it's going to be 2K epoxy filler/primer.

[DrSchmidt]

I have filled and sanded all the seams and obvious geometric flaws. Looks not like much, given the hours of sanding that went into the master so far. But it feels very different by touch and one can see form the putty areas, that there were quite a few uneven regions that are now straight. Next I'll glue some threaded insets into the keel to get attachment points for painting and mounting and the we are ready for the first round of 2K filler....

[DrSchmidt]

Wet sanding the seam....I really hate it. But I make progress.

[DrSchmidt]

A little progress....master building galore: I filled the seams between the 3D-printed segments using polyester putty and now it's grinding, grinding, grinding....

[DrSchmidt]

In a first step I glued all the segments onto the 25 mm x 25 mm steel tube suing epoxy resin. The seams between the segments were filled with epoxy resin that was transformed into a putty using micro balloons. Resin mixed with micro balloons can fill large gaps without cracking, is easy to sand, and gives a good foundation for the polyester putty that will be applied next.

[JHapprich]

What garage?!

wintertime sees attic-action!

[Davidh]

Yes U -23 runs nicely. I thought it would porpoise with the boat hull shape, but it doesn’t. It looks awesome on the water.

Joerg, Thankyou for the compliment. I’m glad it isn’t in your Garage!

[JHapprich]

Its probably the best kit David produced so far. Shame shame mine is still resting on the attic, taped together and awaiting construction