waterlining large resin hulls

[Ron Smith]

This makes no sense to me, why not make the hull two part with a hollow centre? It uses way less resin (resin varies between �8-15 per kilo, that's got to be at least 3 or 4) and gives modellers more options. Kudos for your initiative here, but IMHO you shouldn't have to do it. Everyone wins like that, yeh, it's a little extra work during master making but surely customer satisfaction is worth the extra time?

The problem there is the way resin shrinks a little when curing, in 1/700 and 1/350 you risk distortion if the mass of resin around the cavity isn't the same on all sides. You might be able to do it on the center third of a BB in 1/350 with little risk but I don't think you could do it on most cruisers or DD's in that scale. Manufacturers *could* switch to a resin that doesn't have the differential shrinkage problem but that means a much slower cure time, like 16 hours per casting, not an efficient solution for cottage industry manufacturing.

[Will J]

Hi Ron,

A good point there. I imagine these large casts are made from pretty standard polyeurethanes which would certainly have an uneven shrink rate between the two halves, I aggree with you there. There is probably a resin that would fit the bill, but it may not be economical for a cottage industry as you said. I guess sanding is the only option for now .

[JIM BAUMANN]

Interestingly...

Kombrigs 1/350 resin kit range features very light, stable hollow hulls, upper and lower

the skin thickness of the hulls are akin to injection moulded hulls.

I have no photo of a kit on my PC-but can take pics tomorrow if anyone is interested ...

JIM B

[Sean Hert]

I have no photo of a kit on my PC-but can take pics tomorrow if anyone is interested ....

I would like to see such. What have they done in 350th? There's still a big difference in mass between a 350 BB hull and a 350 DD.

[JIM BAUMANN]

The Kombrig 1/350 kits are really very nice--I have the 1/350 Askold in build- (supended at the moment)

They represent quite good value--obscure and esoteric subjects in finely cast resin.

The weakest kit of the bunch is the first kit released -Retvisan-- overscale deck planking... can be replaced.. but...

3501 Retvizan Russian Battleship 1902
3502 Askold Russian Cruiser 1902
3503 Novik Russian Cruiser 1902
3504 Boyarin Russian Cruiser 1903
3505 Nisshin IJN Cruiser
3506 Kasuga IJN Cruiser

Here a a few quick snaps of my Kombrig 1/350 resin kit of the IJN Nisshin

The upper and lower hulls are cast separately--and both parts are hollow.

[JIM BAUMANN]

a couple more...

JB

[JIM BAUMANN]

Sorry to bump...

but I guessed it was still a pertinent post...!



Jim Baumann

[JIM BAUMANN]

Interestingly... Kombrig are running a customer poll in the manufacturers forum.

viewtopic.php?f=16&t=43121&start=0

waterline or not--maybe this will be of interest to them or any prospective 1/350 resin kit purchaser...

JIM B

[JIM BAUMANN]

With Kym Knight having done a most excellent sequence on waterlining 1/350 hulls


http://www.modelwarships.com/features/h ... index.html



I thought it may be useful to bring this up the board again...


Jim Baumann

[JIM BAUMANN]

bump....!


Still a pertinent evergreen subject....

JB

[Busto963]

I am not a waterline builder, but it seems to me that using a bandsaw to cut the hull in half would save a lot of sanding, and make a lot less mess.

If you do not have a bandsaw, a decent hadsaw could also do the job.

[JIM BAUMANN]

>>>> If you do not have a bandsaw, a decent hadsaw could also do the job. <<<

main issue is being able to clamp it safely and securely without damaging the hull casting details...?

Certainly some resin hulls from manufacturers such as Kombrig are in two parts- and hollow ..
much easing the process.

Its never wrong to innovate further --the sanding merely works for me...


JB

[davidwaples]

Great tip using the resin dust with CA as a filler. I would recommend going to a respirator instead of a dust mask.
Thanks Jim
Dave

[JIM BAUMANN]

bringing this up the board for the benefit of recent members


JIM B

[JIM BAUMANN]

........>>> bringing this up the board for the benefit of recent members ....<<<

every 4-5 years or so anyhow!
JIM B

[Enakan]

Much appreciated!!!