daven

My Feedback: (1)

I got a wing stuck in one half of a wing mold. Standard quickee type wing (52" long, 9 3/4" chord). I've got one corner at the TE loose and I am slowly popping it loose at the TE, but the LE seems stuck tight. I haven't given up on the wing yet, but I'm getting close to damaging it to remove. Any tricks on getting this out?

daven

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BTW, I've tried compressed air with no luck.

soarrich

My Feedback: (98)

Have you tried a piece of mylar?

rcalfred

If you used PVA release film you can pour a small amount of water into the mold and it will dissolve the rest of the film and let you pull the part out. Otherwise you are going to have to destroy the wing and start over. Hopefully the mold will not be damaged. Regards.

daven

My Feedback: (1)

I did not use PVA, it was well waxed, but not well enough. The wing was destroyed, and I don't yet have all the material out. I'm taking my time, and the mold appears undamaged, just a lot of wasted time and money.

thanks,

boater

My Feedback: (2)

Daven, I'm just throwing these suggestions out, don't have any real good answers. I've used soft plastic wedges that I've had for a long time. Maybe squirting some solvent in between might dissolve some of the wax you used, I thought I saw on a previous post you used Dolphin wax. Maybe Klasskote thinner might work for this. Maybe a couple thermal cycles might get some expansion and contraction going on to help things break loose. Maybe getting some water in between and then freezing the whole thing might use the expansion of the freezing water to move the part from the mold. Many years ago I had an aquaintance that molded epoxy helicopter fuses, he use to hit the outside of the mold with a rubber hammer to pop the piecee out, kind of severe, but maybe a few small taps?? Just ideas, worth what you paid for them. Rudy

TGoodwin

That sucks. Sorry to hear that your wing stuck.

Magne

Dave.
Just for interest, did you use Dolphin Wax?
How many coats?
How did you apply the wax, did you leave it to dry on the surface, or did you rub it off immediately after application?
(Just for my own education, as I also use Dolphin wax.)
Magne

daven

My Feedback: (1)

This was the 7th wing I've pulled out of the molds, the 2nd without PVA. The first three wings I waxed the molds a minimum of 3 times before spraying PVA. The next 2 I only waxed once before PVA. The first wing I pulled without PVA I had waxed twice. This last one, I only waxed once.

I am thinking that the main reason for the stuck part was the delay between laying up each half and putting the two halves together. Or, an issue with the aluminum Klass Kote I used. When I was pulling the parts out, the areas that were painted in aluminum were stuck the worst. This was the first time I had used this color in the mold.

davidfee

I am seeing a trend of less wax each time. Although most of the wax probably stays in the mold, some does leave with the part on each pull. Just something to think about.

And, of course, check on that paint by doing test samples... a different solvent (or solvent ratio) can sometimes spell disaster.

RAPPTOR

My Feedback: (41)

YOU CAN SKIP THE WAX ,BUT NOT THE PVA!!!!!PASTE WAX IS AND OLD METHOD.. USE FINISH CARE SYSTEM,,

garys

Dave,
I had an issue one time with a Proud Bird wing sticking in the mold a couple years ago. Not sure why, but for some reason it stuck, now the strange part..it stuck only where it was painted yellow. It's the same yellow Jim Allen and I had used on every one of our airplanes, so the only thing we could think of is one of us mixed up the paint wrong (PPG DCC series). We've used it since with no issues. Had to destroy the wing and re-polish the aluminum mold.
GS

Ed Smith

I am always ready to accept new ideas and the latest technology in any activity. Having said that, I must add that I still use the old paste wax, more for the fact that I purchased a big container of it some time ago. I rarely use PVA. So far I have not had any MAJOR disasters after many years of glass work. I always polish a couple of times before each use of a mold. Sure a couple of corners have hung up but I have never yet had to tear a part out of a mold.

After that statement I am now frightened to lay up anything else.

Ed s

daven

My Feedback: (1)

Gary, The only difference from one wing half the other was that I used Paint Stencils on the top, and none on the bottom.

I have never heard of a stencil pulling up wax when removed, but the areas where I had used stencils were definately stuck worse.

The molds have been cleaned, basically chiseled everything out, starting with a plastic scraper and finished with a razor blade. I knicked the mold a couple times, but nothing too bad.

RAPPTOR

My Feedback: (41)

HI.DIDNT MEAN TO SCARE YOU..I MAKE VERY HIGH END MOLDS AND PLUGS.NOTHING SHOULD EVER STICK,!! NOT CORNERS OR SURFACES.OUR MOLDS RELEASE THEMSELVES!! THATS NOT GOOD EITHER..WE USE PASTE WAX TO HELP HOLE THE PART IN THE MOLD..I LOST A VERY HARD TO REPLACE PART USING PASTE WAX,, #8 HI TEMP STUFF. CLEAN ,SEAL, APPLY POLIMER,THEN PVA OR PASTE JUS FOR SAFTY.. NEVER BE SCARED .. TEST A SMALL PART FIRST..RD

daven

My Feedback: (1)

If you want to paint in the mold with stencils (none of that freehand airbrushing crap) you can't use PVA. Its easier to get away with aluminum molds in that case, but not sure its worth the risk with epoxy/fiberglass molds.

Pictures to come shortly of the mess, thankfully its all cleaned up.

I would love a set of aluminum cnc cut molds, buit can't justify the price at this point.

daven

My Feedback: (1)

Here are the pictures, it was as ugly as it looked. Spent most evenings this past week cleaning it all out. Thankfully the mold is 98% saved, I nicked it in a couple spots when I was forced to use a razor blade to remove some VERY stuck pieces.

Tony Pacini

What is "finish care system"?

Ed Smith

Dave,

I have to commend you for digging in and cleaning up that disaster. If that happened to me I would have fired the whole lot into the garbage.

Ed S

daven

My Feedback: (1)

If I still had the plug, I would have been tempted.

If I had tried to do it all in one sitting I wouldn't have made it.

Took about an hour a day for a week.

RAPPTOR

My Feedback: (41)

FINISH KARE ,,IS A WAX MANUFACTURER. CARS ,BOATS MOLDS..NEVER HAD A PART STICK.. INFACT ,PRE RELEASE IS THE ONLY CONCERN,, PVA OVER PAINT?? DO IT ALL THE TIME.. MAYBE PAINT WAS OIL BASE?? USE LATEX,, CHEAP ALL SHADES. ..RD

BFoote

Yea but, even with Latex what is the finish like with the PVA, slightyly mottled? pasty? Crystal clear? hmm
Latex as a finish paint? There are MANY reasons why NO ONE uses latex as a high finish paint.
For big parts where one doesn't get within 10 feet of it sure otherwise I WOULD LOVE to see some pictures close up!!!! Please Prove me wrong I would LOVE to be wrong. A Lot CHEEPER! Easy to clean up too!!!!!!

Brian
Please some pictures would be awesome RAPPTOR

Ed Smith

The issue with PVA and painting in the mold is this. If the mold has PVA in it and the mold is then masked for trim colours, the PVA will pull off with the masking tape. In some cases the PVA coming off will pull the trim paint with it.

Ed S

daven

My Feedback: (1)

EXACTLY Ed.

PVA is great if you don't want to stencil or tape off color lines, but not really an option if you want something painted in the mold like this.

RAPPTOR

My Feedback: (41)

MANY PEOPLE DO USE LATEX FLATS FOR A HIGH GLOSS FINISH.. EVER HEAR OF CLEAR??? I HAVE BEEN PAINTING JETS FOR YEARS WITH LATEX,,WON MANY AWARDS FOR FINISH AND DESIGN.. "THE WORLD WAS ROUND", BEFORE IT WAS DISCOVERED BY THINKERS LIKE YOU..IF YOU HAVE TROUBLE WITH A PVA FINISH ,IT IS YOUR SPRAYING TECH. NOT THE PRODUCT.. YOU CANT TAPE OVER PVA.. DAH!!..HOW ARE YOU TAPING OVER A WAXED MOLD??? MAYBE YOU PUT DOWN A "CLEAR" OR RESIN FIRST??? TO ARGUE WITH SOME ONE, IS ONLY TEACHING THEM... HAVE FUN RD