Fiberglass a boat Hull

[lmagna]

Bob has given some pretty good advice that is pretty easy to follow by someone who has never worked with Fiberglass before. I might add that you choose a day or time of day where it is pretty much room temperature, not too hot not too cold. I also like to work either outside or in a garage where there is a large door with plenty of fresh air. Letting the hull cure in the sunlight in my opinion is also a plus if it is possible.

 

Definitely add that Kort nozzles and prop shafts after the hull is finished. That is even including sanding. It normally doesn't even hurt if it is already primed when you start working on stuff that attaches or goes through the hull. 

 

Your work so far is looking good and you are making great progress. When you are done you can look forward to doing this: 

 

 

Not the same boat but similar in size and performance.

Edited August 18, 2021 by lmagna

[Riotvan88]

On 8/17/2021 at 7:48 PM, Bob Cleek said:

A half liter Gflex kit should be more than sufficient for a single coat on that model, but perhaps not for two. To be on the safe side, I'd get a liter, although, if you run out, there's no problem applying more to what you didn't have enough to cover, although coats are best connected within a couple of days to ensure a molecular, rather than a simply mechanical bond between the two. (This is especially true of CPES epoxy sealer. Read Smith's instructions.)  The catalyst and resin have very long shelf lives, so you can always put any leftovers to good use. Mix it in small batches and use a flat surface to mix it.  I use a shallow tray lined with tinfoil. When the job is done, I simply discard the tinfoil. Beware of exothermic reactions. These cause a batch of epoxy to "cook off" when the heat generated from the chemical reaction of the mass of mixed catalyst and resin begins to accelerate the curing process and the process runs out of control, getting hotter and hotter until it starts flaming. A flat mixing container spreads out the surface area of the epoxy mixture and permits it to dissipate heat. Fill a paper cup full of the stuff and you can have problems.

 

You can mix some additives together without any problems and not others, but those you can are relatively obvious, like a thickener with a color additive. Always refer to the WEST System instruction manuals which are online. They will provide instructions on everything you could ever want to know about WEST products: Epoxy Instruction Manuals - WEST SYSTEM Epoxy Check to see if there are any contraindications to mixing the additives you are intending to use together. I'd be inclined to apply the two you mention separately, the fairing additive first, and then the barrier coat. Barrier coat goes on fairly smooth and is hard to sand. Fairing additive sands like butter, but if applied in a "peanut butter" consistency, it won't be smooth and will require sanding to fair it. Mixing the two isn't likely to produce a "waterproof easily sanded" surface. I'd be more inclined to expect you'd get a harder-to-sand surface that wasn't waterproof. But, again, check the manuals.

 

I'm not completely familiar with the installation procedures for your kortz nozzle, but I would say it would be best to fair and coat your hull before installing the nozzle because 1. epoxying and sanding is a messy business and working around the nozzle would be a huge pain, if possible at all, and 2) the fairing and coating process will add thickness to the surface of the hull and yield the final dimensions to which the nozzle will have to be fitted.

 

Good luck with it!  And again, consult the WEST System manuals on line! Don't guess. Using epoxy coatings can be mastered by anyone who knows how to follow "cookbook" instructions, but if one ignores the instructions, it can quickly turn you into a "mad scientist" with an out-of-control experiment.

 

I'll also add that you should probably "start small" and get the feel of the stuff as you go along. Mix a small single "pump" batch and apply it on a piece of scrap wood and let it cure, Sand that and apply your barrier coat and see how that works out on the test piece. Don't use your hull to learn on. When you are comfortable, mix no more epoxy than you can use before it starts to cure too much. You can always mix more as you need it, but if you mix a big batch and it "cooks off" before you're done working with it, that epoxy is wasted and the stuff isn't cheap, as you know.

 

 

Thanks again Bob, great advice. I'll definitely test it out first on some scrap. Really looking forward to getting the hull sealed ready for paint. 

[Riotvan88]

On 8/18/2021 at 6:51 AM, lmagna said:

Bob has given some pretty good advice that is pretty easy to follow by someone who has never worked with Fiberglass before. I might add that you choose a day or time of day where it is pretty much room temperature, not too hot not too cold. I also like to work either outside or in a garage where there is a large door with plenty of fresh air. Letting the hull cure in the sunlight in my opinion is also a plus if it is possible.

 

Definitely add that Kort nozzles and prop shafts after the hull is finished. That is even including sanding. It normally doesn't even hurt if it is already primed when you start working on stuff that attaches or goes through the hull. 

 

Your work so far is looking good and you are making great progress. When you are done you can look forward to doing this: 

 

 

Not the same boat but similar in size and performance.

That looks like fun but where do you go to do this is this some type of RC boat event? Something I'll definitely be interested in looking into once she's up and running. My nearest model boat club is almost an hour drive away

[lmagna]

10 hours ago, Riotvan88 said:

My nearest model boat club is almost an hour drive away

That is all too true for many RC modelers into scale ships. We are lucky to have a number of clubs in my area. One I helped found back around 1980, that is pretty much exclusively RC, and Two others that are somewhat further away but also tend to be RC oriented. There is another fairly close club that is more period ship and static oriented but there are many aspects of ship building that cross over and apply to both kinds of modeling. If there is no club locally then see if you can find others that are also interested and see if you can start your own.

 

Back in 1979 we started with two of us, (We just happened to meet on the local pond when he ran over my MUCH smaller ship and sunk me!) and managed to hold our first event on Fathers Day that year, drawing about fifteen or twenty people from the area who we never knew existed, all with boats they had built and were sailing somewhere. That developed into a club that is even today quite active with a large fairly large membership. Even the monthly meetings these days can draw twenty or more people sometimes and the various regattas  and other events are even larger.

 

Not too many pools like in the video around that I know of. (That was somewhere in Sweden I believe) but there are plenty of lakes and such where sometimes things can get quite rough and for RC ships can be very 'North Atlantic'. I have a video of one of my tugs that I made probably 30 years ago that shows it in just those kind of conditions and it was just a local lake. It is VHS and I no longer have a way of playing it but it was fun when I did and always drew peoples attention. Here is something very similar:

 

 

This is a little closer to what My video looked like. 

 

Don't get me wrong. There are many things you can do with RC boats that are not quite as 'exciting' as running in rough weather, but still keep the interest and challenge level high. Try pushing a soccer ball around the pond or even a five or six foot 2X6 or tow a half sunken log. None of those things are as easy as you may think, but plenty of fun anyway.

 

I think that you will find that your build will bring you lots of enjoyment long after the build is actually done. Not that any RC boat is ever done. They get MUCH more wear and tear than your average shelf model.