diggs_74

Ok, I have recently finished my mold for a quickie 500 plane and have pulled to fuses so far.. The problem I've encountered is that I get voids all along my seam. I'm joining the halves wet leaving an overlap of glass for the joint.. The only thing I can think of is that I'm moving(creasing or folding) the glass under the joint and that's producing the voids.. I guess my question is what if any techniques help minimize this?

Thanks in advance..

Oh, here's a pic of the first one out of the mold.. It came out a little "porky" due to fixing the seam line top and bottom but it flew with zero trim on the maiden so I know it's straight.

Ed Smith

Lee,

If I interpret it correctly the top and bottom seam overlap you leave is on the same mold half. You then try to lower the overlaps into the trimmed half. Correct?

Let me see if I can explain what I do. One side if the mold will have the fuselage top seam with an overlap and the bottom seam trimmed. The other side of the mold will have the opposite. When joining, lower one mold half into the other with the overlaps well clear of the opposite half and then move the mold half sideways. The overlaps will then both sit against the trimmed edges without folding as you aligne the two mold halves.

That is if you understand my explanation.

Ed s

Deadstik

My Feedback: (8)

Lee,

I'd like to echo Ed's suggestions as that is very same way I put together my vintage pattern ship kits.... but I would like to add that preparation of the "overlap " is very critical. What is so critical is that you have to make absolutely certain that the wet glass/cloth has zero voids in the "mold" section. I'm not sure what your layup schedule is, but on my 3rd layer, once both sides have been applied, I saturate the glass above the mold about 1/2" with epoxy (where I want my overlap seam to be). After the glass is saturated, I then cut the overlap seam using a 1/2" piece of light ply as a guide. I then go back and carefully check every area inside the seam line for voids and other places where the glass may have "lifted".... it is these "lifted" areas that you have to go back and eliminate. Also, when you do join the two halves together, Ed's angle/slide method works very well... but even then you have to over every inch of the seam line with a tool ( I use a small wooden wheel on a tool made of 5/32 music wire) to carefully press down the seam line. Using a powerful flashlight will enable you to see every flaw in your seam layup.... and just remember to NOT get in a hurry... this stuff isn't going to hardner for 12 hours... so you have time... One more thing... I have access holes for my tools/inspections in the front and back of my molds.... makes no voids a LOT easier.... but even with the most careful preparation you can still have a little one here and there.. you just have to take your time and make sure you've got everything perfect before you let it set up.... Hope this helps... Practice is what makes perfect here...

Dan
Carolina Custom Aircraft

SCALECRAFT

My Feedback: (13)

Or you can use a joggle gasket/ flange type of seam joint

Steve

Deadstik

My Feedback: (8)

Steve,

Can you please explain (with pictures if possible) exactly what a joggle gasket/flange is???? I've seen this mentioned (and heard of it) many times but have yet to get a good solid answer as to how to do it and why it eliminates any void issues. I'm ALWAYS on the lookout for a better technique... so... please enlighten me/us....I'm sure many here on the forum would like to see this.

thanks,
'
Dan
Carolina Custom Aircraft

TeamSeacats

here's the site where I first learned about the joggle from a guy building a composite wing for a full-sized glider.

http://www.hpaircraft.com/hp-24/update_11_august_06.htm


and my website where I did ~some~ documentation on creating a joggle for my r/c sailboat hull on a much smaller scale.

http://www.teamseacats.com/index.php?s=joggle

Kevin Matney

My Feedback: (1)

Is that a Conspirator fuse From ARC??????

diggs_74

Thanks for the comments.. I do trim the top flush on one half and then the bottom on the other half as Ed states.. I stopped by the hardware store to get the fix-in's for a home made roller of some sort so I can get everything laid back down.. My first to fuses I tried using a brush which I think is the main issue with the lay up.. My schedule is a layer of 3oz then any CF reinforcement, then a layer of 6oz and then another layer of 3oz.. So far, both fuses I've done came out right around 7.5oz with the LG and wing hold down blocks.. I was told that anything under about 8oz was fine for the 3.75lbs quickie weight limit..

Kevin,

This is not a Conspirator but obviously I used some features in my design.. My first quickie I raced 428 with was a Conspirator a club member gave me to use. After crashing it a few times I donated it to another new racer.. I really liked how it flew so I guess that's where the sub fin came from..

Deadstik

My Feedback: (8)

Jake,

Thanks for the info.... I've got it now....I can see where on a completly blind composite wing that the "joggle" can be invaluable... but... considering I can get to the seam line on all of my molds (except one).... I think I'm going to stick with my "careful" method... If I get time, I'm certainly going to look at making a joggle mold for that one mold I can't get to the seam line in.. that may be just the ticket for stopping voids in that layup....

thanks again for the info... now if I can just get the shop warm enough to paint.. it was 16 this morning in Carolina.. who knew????


Dan

TeamSeacats

no doubt - I just got a shipment of carbon and resin but sitting here in the cold Carolinas with a head cold and inner ear infection...about to go stir crazy. Fortunately my ailing heat pump just got replaced and the new unit working yesterday.