Getting ready to build at last!

[modelnut]

I am finding the supplies that I have collected over the years for my first R/C sub. Getting married and moving from a one room apartment to a real house? It has taken a while to get things sorted again.

I have Great Planes Epoxy fiberglass. Three sets of 4.5 oz resin and hardener and three square yards of 2oz (medium) cloth. Will this do for a 97 cm hull? And 11 cm diameter?

Where do I get "gelcoat"? A boating supply store? I think there is one on the other side of town. I bought some expanding foam there once.

My studio is almost ready. I will be redesigning my NAUTILUS by Wednesday morning. Buying foam this Friday. Hope to start cutting as early as Sunday. I will take pictures and try to start a builder's thread.

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Quick question, am I right in remembering that only the rear dive planes are operable in R/C subs?

I had thought to yoke the forward and rear diving planes together but the one hull that I have seen and touched has only the aft planes moving.

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I also remember that +/- 35 degrees is as much range as necessary for diving planes and rudder. That was my question on a thread years and years ago.

BIG DAVE! I hope to be buying a 3 inch WTC from you come the spring. I have seen what you've done for Steve and I like it! Should have the +$500 by our tax return.

Please. I know what I am doing is old hat to most of you. But I could use all the advice and kibitzing you care to throw my way.


- Leelan

[thor]

Re: Getting ready to build at last!

First piece of advice is to read carefully through the many scratch build threads posted here and on SubPirates. They will provide a lot of very valuable data. Next I would recommend going to www.fibreglast.com and purchasing their great set of mold and fiberglassing videos. They are excellent and well worth the money.

Two ounce cloth is like tissue paper. It is a surface treatment only. Not used for structure. The amount you have will provide a wall thickness of less than 1/32nd of an inch when all layed up. I suggest you get some 4 oz cloth and 10 oz cloth for structural rigidity. All 2 oz cloth is used for is to provide a nice shiny surface when used in laying up a part in a mold. It has very little structural value.

Welcome to the world of itchy and scratchy!!! If your resin is polyester resin, make certain you have EXCELLENT ventilation and a good air turnover. It can cause a myriad of health issues if not taken seriously. Wear goggles or safety glasses when mixing and applying. MEKP can blind you permanently, and is not to be taken lightly. Wear a good pair of latex gloves when you work with it so you don't develop a sensitivity to the resin. It happens. It happened to me 20 yrs ago. It is not a fun condition to have....

Matt

[modelnut]

Re: Getting ready to build at last!

Thanks, Matt!

I just visited the Fiberglast website. The DVD set is $99! I think I will go for the book instead.

Though I haven't found much online what I have found tells me that working with this stuff is very hazardous. I have a roofed but open back porch that will serve as my glassing area once the weather cools a bit. I don't fancy getting all kitted up and working for hours in 100 degree weather.

I have seen a few scratchbuilds post here. But most I remember were in the old gallery. I distinctly recall someone having a hell of a time with his build because he used Kevlar cloth for his final layer.

- Leelan

[Guest]

Re: Getting ready to build at last!

You just need to take sensible precautions. This stuff hasn't got anything in it that is wholesome and good for you, but it isn't grade a plutonium either.

As advised good pair of gloves and a well ventilated work place are all you really need. Polyester is quite pungent spelling, I can't speak for epoxy as I haven't used it, but it is reportedly far less pungent.

Personally I don't find the smell of polyester that objectionable- I've smelt worse perfumes, but then I have a funny sense of smell.

The worse thing about glasswork for me is the mess it creates, and the fact that little bits of glass seem to get everywhere, and boy does it itch!

[modelnut]

Re: Getting ready to build at last!

Oy. Is FiberGlast serious about their minimums??? Ten yards of 4 oz cloth at $6.95 and ten yards of 10 oz at $8.95! That's $160 not counting shipping! That's NUTS!

I can't spend that much on cloth alone. Will take my business elsewhere.

- Leelan

[thor]

Re: Getting ready to build at last!

No! That is only if you are having a custom length cut!! Look below that section they have precut packages available at a MUCH reduced price.

Matt

[modelnut]

Re: Getting ready to build at last!

OK. You mean the packages? Pre-cut lengths? Three yards of 4 oz for $24.95. 10 oz for $32.95. Better.

Sorry about that. Knee-jerk reaction.

I know building a sub from scratch is expensive. But how else can you get one that does not exist as a kit?

I'm going back to my drafting table now. Will see if I can get the idea stewing in my brain out onto paper.

- Leelan

[thor]

Re: Getting ready to build at last!

Leelan,

Just out of curiousity, what are you wanting to build?

Matt

[modelnut]

Re: Getting ready to build at last!

I have posted my dream so often that I forget someone might not know. I usually post to the TV/SciFi Subs portion of the forum. But since I had specific questions about scratchbuilding and R/C I posted here because I thought I would get faster replies.

Here is the sub I have wanted to build since 4th grade:



The aft end will be different though. That is one of the reasons I am back at my drafting table.

- Leelan

[thor]

Re: Getting ready to build at last!

Leelan,

That is a great looking boat! You should contact Steve Neil. He has built something very similar to that! I know Steve's boat drives very well. It is certainly a wicked looking boat...

Matt

[modelnut]

Re: Getting ready to build at last!

I know Steve's boat. I have many pictures from his website as wallpapers on my computer. I have emailed him a few times and I bought (and lost!) his CD, "R/C Subs for Dumb Asses". I may have to buy it again.

Just read your articles on making a fiberglass mold. If I understood it correctly, I think I should lay one layer of 10 oz cloth, two layers of 4 oz and one layer of 2 oz. Then that surfacing resin you mentioned. Are scales absolutely necessary? Won't volume measurements do just as well? Ounce for ounce?

I am tinkering with the final design. Will be another week before I start to glue foam.

- Leelan

[modelnut]

Re: Getting ready to build at last!

If that layering of cloth and resin is OK, how thick will that make the hull? I need to take the thickness into consideration before I start shaping the blank. No one will know but me. But I want to stay as close to 72 scale as possible.

- Leelan

[thor]

Re: Getting ready to build at last!

Leelan'

If you follow the mixing instructions and you will be in good shape. Most all resins have a mix ratio that is not 1:1. Most are 5:1 or 4.3:1.

If you make a pattern and then pull a mold of it, then you will not have to worry about skin thickness and compensating by using an offset. However, if you are using the lost foam method you can use .07" as an average for that laminate schedule. If making a pattern for a mold, no 2 oz cloth is needed. Replace the 2 oz cloth with a laminate of 4 oz. The two oz is only needed if you are making the mold, or are laying a part up in the mold. If you are just freehanding it, don't bother with the 2 oz. Resin content is very important. Go heavy and you will have a laminate that is thicker, go dry and it will be thinner. The rule of thumb is to just wet the cloth out and no more. If you have dry spots, use a tad bit more resin. You do not want runs in your resin work!


Matt

[modelnut]

Re: Getting ready to build at last!

This will be lost foam all the way. My boat will be a one off. No molds.

In your article I thought I read that the 2 oz was good for hiding the grain or weave of the heavier cloth. If it's not necessary then I will just be content with a layer or more of the surfacing resin. There may be a bit of engraved detail to be added later. I am still thinking about it.

- Leelan

[modelnut]

Re: Getting ready to build at last!

Thor,

Here is my final design. The only thing that may still change might be the addition of Verne's keel. But that will probably be external to the hull.



Still on track to cut foam this weekend.

- Leelan

P.S. Should this thread be moved to TV Subs?