Square Nozzle

My Feedback: (1)

I have to ask. Are we looking at a 2016 Christmas present? If so, your Dad has done a fantastic job for only 2 months of building. And now my request to clear my mind. Some day when the WetJet is done would you please put together a tutorial, using a selection of your pictures to explain what each process you used is producing. I understand what you were doing in the initial steps from foam forms to making the first molds but you have left me in the dust from there on.

Vettster

Thanks John.. I'll pass it along to my dad. Yes its 2016xmas.. but its an ARF from HK. lol.. My old man has built countless amounts of kits over his 55 years of flying RC.. So this little ARF wont slow him down much I have to say.. this ARF looks GREAT! for only $200

Id be more than glad to help.. but honestly the problem is that RCU doesnt let you add comments to the pictures like RCGroups does. So your missing out on the process I guess. Check it out here.. https://www.rcgroups.com/forums/thum...one&starter=no
You can then click on the photos(many familiar/ some not here on RCU) Under the photo at the bottom left you can click on Goto post and read the details.

Pretty much... once I started making molds, its the same process over and over.

Wax with high temp partall (pure Carnauba wax) 6 coats MINIMUM and wait the FULL half hour between coats!

Apply tooling coat. Its a very hard coat that will take all the beating of you trying to remove a pulled part or plug. There's to many brands out there to recommend one. Go to your local composites store and ask for tooling coat for molds. Again this might depend on weather your using epoxy or poly.

Since fiber glass does not like to bend sharp corners you must fill these corners to allow the glass to sit smoothly with out bubbles. This is called Cabosill.. and its the Red Stuff you see going all around the perimeter and places that need smoothing out. Its from West Systems and is a Low density Filler 407

Then the glass is laid for the mold. You need to get at least 3/16 thick.. and believe me it takes a LOT more layers than you may think lol. 3 layers of 6 oz -----followed by 3 layers of 10 oz ---followed again by 3 layer of 6oz Your mold MUST BE RIDGID! Not using enough layers will make for a flexible mold and the Tooling coat will crack! Thats not Good!

Thats pretty much it.. Other than small things like adding alignment plugs and bolt holes and how long before cracking the egg etc.

I would have loved to have posted pics to this response but its just to labor intensive on this forum. Feel free to join me on RCG's and ask all the questions you like. Here is a Step by Step mold making https://www.rcgroups.com/forums/show...4#post33867686

Once I have a completed kit that has flown.. I will post a separate Build thread dealing purely with the assembly of the WETJET.

Vettster

This was a big one today! This means the Fues is Finished Just need to work on the engine pod and vert stab and elevators now

Vettster

Here we are full week later. I have to say.. though you can pull the plug in just a day or two later.. it is much easier when you wait the full week.

Having said that though! I was correct in my decision to split the bottom mold as the plug did not want to come out as one piece mold.

Once I spit it, it was easy.

I just realized an even greater benefit of splitting the bottom mold... Now I can EASILY make the formers needed with construction paper

I am a VERY Happy Camper Today

Vettster

Preparing to make the mold for the engine pod. The Pod and the vert stab will be one piece since there will be many stresses in this area.

Vettster

I really need a break from the molds. Skinning the wing I laid up earlier. 1/16 balsa epoxied and the vacuum. This very light Balsa will add tremendous strength to the wing and not weight much at all. With this wing/plane I have to consider all the impact that the wingtips will take and transmit threw the wing.

The third pic is my Uber Vac taking up the vacuum. It cost about $25 Can.. oh yeah!

Vettster

Two more wings skinned. Soon I'll be making the ribs and wing tube receiver. After that i can glue them together.

Vettster

Great day today. Got all the skins ready and there starting to look like wings

Vettster

Off for the week.. Hope to get TONS DONE!!!!!!!!!!!!!!

Made the wing tube receiver from 2 wraps of 4oz

Started roughing out the wing forms with cardboard. I will transfer them to paper. Im very lucky that my neighbor told me last fall he bought a laser cutter.. He's got some business coming his way

Vettster

Paper traces transfered to partial board. Now I can sand down to properly fit when mold is closed. After that they will be traced onto paper again and sent off to be laser cut.

Square Nozzle

My Feedback: (1)

Page after page of photos of your beautiful work and few remarks from the peanut gallery. You have them lost for words I guess. I am amazed at the process you are going through and your workmanship is outstanding. I am on the edge of my seat waiting for the finished product to get wet.

Vettster

Hey John! Thanks very much! I don't mind so much.. I know that someday perhaps someone will reference this thread when they start on their own scratch, and maybe this will be useful to them.

So! How will I know where the high and low spots are on the formers to be sanded or added to? Add balls of putty Place small pieces of wax paper on top so it doesn't stick and bango! its that easy. I actually was very lucky.. Just the slightest sanding near the tip and I have to add about 2mm at the rear. Very easy. Once I correct them, I will then transfer to paper for the laser. I will have about 4 sets made.

Vettster

Going to be laying down some serious cloth today. Hoping finish the top and bottom fuse.

I two sided Taped the hatches down. I used aluminum tape around the edges so the resin wouldn't seep in a hold the parts. Then the hatches were given the putty treatment around the edges. Always use the putty

Got lots of bits and pieces of CF to put down to.. so the finish will look much different from the photo below.

Vettster

Now we wait...

Vettster

Well I finally made a catastrophic error! I changed the game rules in the 3 quarter. I decided not to use the usual pink filler(405 west system) and instead went with microballoons. Normally that would not be a problem.. but I forgot to add cabicil to tie it all together and the cloth sucked the resin right out of the balloons The result was the corners all stayed behind in the mold I'm going to have be careful with the bottom, but I did add some cabicil to that.. lets just hope it was enough. Not enough and it can crack as what happened to the top.. To much and it will never cure hard.

So anywho.. Since this is the prototype im not going to waist more time and money to make another. I will return it to the mold with repairs to the corners and hope that fixes most of it. After saying all that! I have to say.. seeing it with the canopy on is pretty darn inspiring.

Vettster

Take two... Decided not to waste anymore time repairing the top. Layed up a new top this time with MUCH faster hardener. Can pull it out of mold in just 24 hrs.

Each half takes 4 hrs work from Waxing, Putty, PVA to cutting cloth then cabicil and then 2 hrs to lay down the cloth.

FYI.. Im just making note of the hours as a personal log. I hope to improve with each one.

Square Nozzle

My Feedback: (1)

Trevor, this is like watching a mystery on TV. What is going to happen next? Is the putty and PVA used to fill the sharp corners before you lay the glass cloth? I have never undertaken such an involved fiberglass project. I've made scoops and blisters and sorta understand the need to prefill tight corners because the fiberglass will not.

Vettster

You're kinda on the right track.. Whenever you have two separate pieces ie a hatch that is molded in.. You need to go around the perimeter so that the resin doesn't sneak under the hatch no matter how good the fit!.(same as when you attach a parting board) Then when you have a 90* angle you have to fill that with cabicil because fiberglass does not like to bend in such tight turns and a large air bubble or void will be there when you pull the part.

Vettster

Layed up the ailerons last night. Skinned them today with 1/16 balsa sheet and added 5/16 x 3/4 hard balsa shaved to fit hinge line. Glued em up and they will sit clamped in the mold for the evening.

Some good photos of the cabicill in the corners for you John.

Vettster

Well the second one firmed right up. But I don't trust it to hold its shape in the sun since it's supposed to be post cured to 400F. However it came in useful to size up the formers.

I spent the day going over the master mold giving it 6 more coats of wax and re taping the hatches. I added some holes to the corners to help ease the release. This is number 3 and I ain't taking any chances.

#3 is all ready to get wet tomorrow Ohh and I have ailerons!! Yippi

Vettster

Well I couldn't take it.. I had to see how the bottom fuse looks. Thank god I did a split mold. It came out pretty easy. I'm crying as I write this..I'm just so happy . It's freaking awesome!!!

Vettster

What a gigantic difference. The resin is very firm compared to the slower set stuff. The corners are all intact!! Yippi Just much much better all around.

The only thing is.. im going to have to go with the tradition method of making the hatch seams. I wanted what I refer to as a layer over a layer type hatch so that water would be trapped in the seam, but its proving to be much more trouble than anticipated. So I will be making the hatches in your tradition matter like you see on all ARF's

Vettster

I have a wing!! After a FIVE WEEK WAIT for my laser cut parts!! I won't be using that guy again.

Man! This new forum really sucks! They have actually gone backwards 10 years with the photo uploader. I really don't see me posting here much anymore as I am busy enough as it is and don't need to waste my time uploading one picture at a time.

So if you want to follow along with my build.. best to go to the much more user friendly RCGroups. My build can be found here.. https://www.rcgroups.com/forums/show...powered-WETJET

Thanks for following along guys!

Trevor

RedDwarfIV

You can upload them to sites like Imgur (which allows the uploading of multiple images at once to produce an album), then copy across the links into [ i m g ] [ / i m g ] tags. It will automatically upload them all for you without having to mess around with the Insert Image tool. Copy paste the tags to get multiple of them quickly. Also, remove the spaces from the example tags earlier in my post.

Vettster

Thanks! I already have an account with Photobucket, but again its too much work. Just easier for people to view the build at RCGroups. Its extremely easy to upload photos there and even has a view counter. https://www.rcgroups.com/forums/show...powered-WETJET