mogles

My Feedback: (7)

I am interested in building my own glass fuse. Can anyone point me to where I could find what I need and perhaps a few directions on how to create the mold, I would greatly appreciated.

Thanks much.

Jimbonk

If you are talking about making "A" Fuse then the best advice I or probably anyone else could give you is to carve a Plug out of Blue Foam and cover it with Glass and Epoxy. After the Epoxy has cured you remove the Foam with a combination scraping and using Acetone to dissolve the foam.

If you are really interested in fiberglass molding there are some VHS tapes available , and there is a thread in the Composite section on this very subject.

Jim

Kruges

hey mogles, i will tell u the method i use. the t-bird under my name is made in this manner and is a great sloper. first off i cut 2 templates of the side view of the fuse and then 2 temps of the top view. i usually use bristle board as it is easily pinned to a block of foam. i pin the sides on first then wire cut it. then the top and bttm. now u can sand your pink or blue foam to the shape u want. now take packing tape and cover the complete model. dont miss any or the resin will prematurely eat the foam. u can use your monokote iron to help keep the wrinkles out around the coreners, just use really low temp. now i take a layer of heavy cloth and glass the entire plug. followed by another layer of heavy cloth. then a layer of thin cloth. now mis a batch lf microballoons with resin to make a thick paste. coat the plug. this wiil make a easy layer to sand and helps preventing u from sanding into the cloth. after it all dry sand to a glass smooth surface. now cut out wing saddle and pour acetone in to eat out the foam. usually u can grap a corner of the tape and pull it all out at once. it is way easier than it sounds and i can buidl one of these on a weekend.i will attach some pics but if they do not work email me as i have taken pics of the process in order.

Kruges

this is the only way i know how to get the pics on here, so,,,,,,

Kruges

pic 2

Kruges

pic 3

Kruges

pic4

Kruges

pic5 final coat of microballoons and resin

mogles

My Feedback: (7)

Perhaps someone could shed some more light over. I've been reading recently as I do would like to start some fiberglassing but still have some questions.
Do you guys make the positive mold? Anyone using the negative to get the best finish?
If it is two sides mold, how to you combine the two to get seamless fuselage? I noticed that even the high performance glider still shows a seem at the center.
I was thinking to make a mold out of plaster.

Thanks in advance.

Kruges

in order to make a mould out of plaster u still have to make the original fuse so u can then make the mould. if u are going to make alot of the same fuse this is good but if its a one time deal then u have already made the original fuse by the method above or something simular.

mogles

My Feedback: (7)

Kruges

Thanks for replying to my posts. I am more concern with the finish. I would rather do a negative mold so I can get the smooth finish. If there are other options, I would like to experiment them. Is your methode giving you a nice finish without compromising weight? I am trying to build a handlunch fuse. I want to get it light and strong.

Thanks again.

Kruges

i have never built a hand launch glider before as i only fly on the slope and powered, but i have built many 60'' racers using this method. if u wanted to lighten this method up i would use one layer of cloth. on my fater ships i lay strips of carbon fibre cloth along the fuse for strenght. these fuses are bullet proof. mixing the microballoons with the resin makes a very easy layer to sand. the only limit to the finish depends on how much u want to sand. i start with coarse paper and work all the way up to 420 grit which gives a glass smooth finish. i use automotive paint and u cant even see a scratch. one thing i forgot to mention is before cutting the plug i draw a cinter line on the foam as a referance. then i make cardboard templates of half a fuse side. make these every six '' along the length of the fuse. then i place the temp on the side and sand to shape. then put on the other side and sand to shape. this will help u keep both side of the fuse exactly teh same shape and size along the fuse.i have enclosed a diagram to better explain this. this really does give excellant results and u would have to make a fuse so u could make the mould anyway. which ever way u go good luck. i'm sure u will be happy with the result. a scratch built plane to me, is always more gratifying than a kit. Kevin Kruger

mogles

My Feedback: (7)

Kevin,

Thanks for all your info. I should be good to go for a while. I am starting to gather all the parts needed. I totally agree with you about building your own stuff. I have an artemis that I fly quite often and boy the finish on this glider just itches me to try to find how in the hell these people did it. Really not interested in building the entire thing but I would very happy if I can only do a elevator or even a wing tip, just to do it and hopfully to get at lease close to the glass finish.

Thanks again

Stefan

Kruges

Stefan, try the inland slope rebels site, http://ourworld.compuserve.com/homepages/ISR/ ,they have some contruction articles that desribe how to make moulds. good site!

DaveHill

In high school shop we did some thermal plastic vaccume molding, you get a sheet of plastic several feet square good and warm and then flip it over onto a vaccume table that looks like an air hockey table with reverse suction and the plastic molds to the plug you've put on top of the table. The result is like those plastic trays you see everywhere that hold products in boxes, but you can make them much thicker and stronger than that. I'm thinking of taking my Bird Of Time fuse and making thermal plastic molds for the left and right sides, cutting them out, taping them together to form a complete mold, and then covering that in fiberglass.

Daves Planet

Graph the wind speed in your area using this software

FLYBOY

My Feedback: (11)

http://www.cstsales.com/articles_for_model_builders.htm

Check out this link. I think it will help you.

The line you are talking about on top and bottom of the fuse needs to be there. If you try to do the fuse in a 1 peice mold, you can't get to the glass inside it to lay it right and wet it out and other things. You need to make a 2 piece mold so you can get the glass in and then put it together and put a strip inside to hold it together. I don't know of a way to do a one piece besides using a carbon rod for the tail tube, but I don't like the looks of that. Doesn't mean it can't be done though.

DaveHill

If you use the thermal plastic molding I described as the base and then build the fiberglass up from that just like blue foam then you have a one piece that would be stronger.
Advantages of using a thermal plastic sheet base
* fast and easy to replicate a fuse in thermal plastic sheeting
* can make many molds quickly, not like a one-of in carved blue foam and drastically simpler than traditional concave fiberglass molds
* single piece fuse built up over the two halves of plastic, stronger and no seam

FLYBOY

My Feedback: (11)

Guess I wasn't understanding your plastic process. You glue the plastic together and then glass it in one shot? Do you then take the plastic out?

I was talking more of a female mold that you lay the glass in, let it get to the green stage, trim it, put the two halves together and run a seam inside.

How many layers of glass do you use in your method? Seems like you go through the same process of building a plug, but then you have to make a new mold ever time, which wouldn't be hard with your method.

DaveHill

Flyboy,

The plastic would have to stay, I have to find a good balance between rigid and light. I don't mind a little weight as long as it adds to the integrity, I may even try thermal plastic molding with plastic heavy enough to use by itself, just glue, paint and go, but of course the molds to go inside of fiberglass would be light as possible and still support the wet fiberglass. There are also wood reinforcements in strategic places inside the plastic halves that will also add to the rigidity.

The thermal plastic mold is the method I like because it is drastically easier than building female molds and won't harm my plug. I'm trying to figure out the best weights of cloth, number of layers, types of epoxy.

One unnecessary complexity that could be added to keep the weight of the plastic to an absolute minimum would be to add slight air pressure inside the sealed halves to just counter the wet fiberglass (continuous pump would be best, maybe an aquarium pump with a relief valve in the line, but a balloon method that just doesn't let air back out might even work).