Best waterproof finish

[packardpursuit]

Was wondering what the best current finish is for FF model water planes? I seem to recall that the Flight Masters used to have an ROW scale contest yearly. anf IIRC the best/most common waterproof  and still acceptably light finish was japaneses tissue with several coats of dope. Has there been any more recent advancements? Possibly Scotchgaurd? 

[BG]

CHarlieman, I heartily recomend Helmsman Spar vernish. Slop it on wipe as much as you can off, let dry and do it again. After that it should be waterproof. If applying over tissue then thin it with some thinners to make it easyer to paint on and wipe off.

Bernard

[packardpursuit]

IIRC, 5 coats of thinned clear butyrate dope on tissue was about right for a reasonably fuel proof  FF model, but left a lot to be desired as a moisture barrier. I remember my models wrinked finish as they lay in the damp " tall grass" after a flight, but then retightening a few moments later once out of the "jungle conditions".

Was wondering how suitibly light finish on average rubber model would hold up to the 15 min floating requirement for Schnieder event? Or would it have no influence on the model itself, once airborne  or other typical/practical conditions that have the model separated from 100% humidity?? 

[dputt7]

When I built my Schneider float planes I used balsa covered scale floats with lots of dope and painted with enamel, not very light but worked OK. Some fellas used foam floats painted with a water based paint. I was thinking that Mylar covered floats should be water tight as well as light, I've not used it but could be worth a try.  One point I learnt on my first water plane was to seal the cockpit and make sure the nose block does not fall out. The inside of the fuse can hold a lot of water!
regards Dave

[neons]

I would try a sampler peice of tissue that is glued down flat or to frame. Try using a non oilbase paint. I use Miniwax waterbase polyurethane clear finsh. You can add talc if you want. Spray or brush on will give a light finish when dried.  It gives an acrylic coat. I prefer airbrush spray as it is not soaking. Can even add a little talc powder if you want to do some sanding for a smooth finish. It is something I like that is modern day.
Neons Bob

[packardpursuit]

Hey,
I just moved to a new local, in the Sierras, southwest of Yosemite Nat'l Park.  Last Friday, wife and I were invited to watch the grandkids and extended family swim at a near by lake, only a few miles from home. Wonder of wonders,, has a long flat sand bar beach, extending out perhaps 50yds. Very shallow on all three sides, with depth to two ft deep, several yards out. Afternoon wind was barely perceptible, but blowing out from shore, along the length of the bar. Lake is not huge, and is surrounded by tall pines, but is large enough for smaller FF model flight operations. I WILL be building some rubber powered  "seaplane" models of varying types. Son-in-law has small canoe and three grandsons (10- 12-14 yrs old) for retrieval duty. I'm partial to Macchi M-39 and/or Supermarine S-5, and other scale types but will probably start with simple 30" foam wing stick type on foam floats, and 9.5" plastic prop.