Composites Plugs and Molds.

[Mitch]

G'Day Gents,

In the process of restoring instrument face plate and pod back to original condition to use as plugs for making molds out of each.

Both pieces are just about ready to go,* need to place them on a parting board and layup the molds.

Interesting process. I'll keep you informed as to the success or otherwise of this effort.

Cheers,

Mitch.

[Mitch]

G'Day Gents,

Some of the stuff I've read recently about plug and mold production and composite work in general reads like.....make it pretty, make it ugly, make it pretty, ect OR wax on, wax off, wax on, wax off.

This whole process can get out of hand, sooner or later I think one needs to just do it. Suck it and see.

These pics show the restored face plate, mounted on a parting board via glassed in bolts at rear of plate, a nut on each bolt holds the original plate in place. I then ran a bead of bondo around the seam, where the face plate contacts the parting board.

Tonight I did the final sanding and wet and dryed till it all polished up nice, then started waxing. 7 coats tonight. Probably do three more early morning and allow last coat to set up for 1 hr before polishing up, then a quick brushed on coat of PVA solution, let it set up a little and then this plug should be ready to glass up a mold on.

Cheers,

Mitch

[Mitch]

Few more pics.

[Mitch]

Lay up the mold today.

Made a few blues,.....have to wait and see.

When adding talc to polyester resin dont be shy. My first application of black coloured tooling gelcoat ran off the edges and down the sides. So I added more talc and more talc and then when brushing extra on, pulled up some lumps. It takes a bit of practice and working out your time frames ect.

Couple of pics.

Mitch

[Mitch]

G'Day Gents,

Popped the mold off the plug this morning and very happy with the results. Despite dragging up some of the tooling gel coat yesterday prior to laying cloth and mat, it all turned out pretty good. A polish up with some wet and dry and polishing compound, and one or two tiny holes to fill and then I'll turn out a part.

Instrument pod is next, it has been reduced back to an ugly state, ready for mounting on a parting board.

Cheers,

Mitch

[Mitch]

Polished.

[Mitch]

Mold Mark 2 for face plates and will know tomorrow if I have a successfull part and a good instrument pod mold.

Mitch

[Sonnyj]

Very nice work Mitch
If you keep going like that, I'm gunna have to have one for my gyro.
Do ya think you could sell me one? :buddy:
C'Ya Cobba
Sonny

[rotor]

Mitch, looks to be comming along nicely. Prangs are not good, don't worry I know along with a growing number of others :dizzy: If nothing else it motivates some to expand their abilities into areas they've never been before.

Keep up the good work mate, you'll be back flying in no time.

[Mitch]

Morning Gents,

Here is the first part Face Plate..FP1
Three layers 200g cloth, clear coat.

Next one will be four layers cloth and thicker gelcoat (black polished finish).

I agree Rotor, this is why I post to share the experience and hopefully save others some grief. Composite work is more fun than I thought and very rewarding when you are finally manufacturing your own parts.

Sonny my ole Mate...you could have the shirt off my back my Brother...let me know when and where. Cheers Digger.

[Mitch]

Rotor,

I just picked up on the dizzy thing.....what happened, you OK?

Mitch.

[rotor]

Hi Mitch ... yeah, I was refering to bones's post and his machine in pieces, sorta makes you dizzy thinking about these unfortunate incidents :sad: ... I dropped one into a plowed field last year and it rolled over after one of the mains hit a farrow so I know how you all feel.


Cheers

rotor

[Mitch]

OK Rotor,

Not sure what's happening with Bonsey's situation, he hasn't got back to me.

Popped the mold for the instrument pod all came away cleanly. Looks like we are in production now with pods and face plates. :yes: :joy:

Mitch

[rotor]

Mitch, my apologies but I missed 5 piccies that you posted when I upgraded. I did a complete rehash of the site starting afresh with new software* and as far as I can see those are the only things I missed. I know it's a pain but I'd (and others would)appreciate it if you could upload them again.

If your not sure - just modify your post , untick the pictures in them and upload new ones.

Thanks mate

[Sonnyj]

G'Day Mitch
I'll get to the shead in the next few days and make a plywood mockup of the face plate,to see if the guages will fit.
I'll let you know how it comes out.
Thanx Mate
Cheers
Sonny

[Mitch]

Face plate...Instrument pod Mold.

[Mitch]

G'Day Gents,

Turned out a black gelcoated face plate. Four layers of 200 gram cloth, heavier and more sturdy than the first clear plate of 3 layers.

Wiped the PVA on this time but the results were not much better than brushing it on. I still had to sand, wet and dry, then cut and polish to get presentable product.

Cheers,

Mitch.

[Sonnyj]

Mitch

Man it's amazing wot a feller can do with a little glue and cloth, and about a hundred pounds of elbo greese.
Bloody Beaut mate.
Cheers
Sonny

[Mitch]

Hey Sonny,

Going back to the start. Redoing the plugs..full paint and polish, rather than just polished. Also to level out the face plate, had some dips and valleys, which is reflected in the finished product.

Talk soon.

Mitch.

[Mitch]

Got the plugs reworked with a coat of primer. Face plate plug in the middle 2nd pic, shows better quality and shape to first face plate Mk1.
Thanks to Pete Barsden ASRA Asst Tech Mgr for the advice re composites, hope I can put some good parts out now.

Mitch.

[Sonnyj]

Yo Mitch
I reckon I shoulda said 200LB of elbo greese.
Immaculate job mate, keep up the good work. :clap: :lol:

Cheers COBBA :cheers: :peace:
Sonny

[Bob]

Yessir Greg ! them is the purdest insterment pods I've ever seen ! smooothe as a baby's ... well almost ! hehehehehe

good work buddy ! I'm proud of ya !

Bob....

[Mitch]

G'Day Gents,

I now have two molds black gelcoated layups. Gelcoat is a bought one not a home brew, so we will see if it stands up to my harsh treatment better than my original efforts.

Face plate mold had a couple of tiny pin hole defects and Peter Barsden advised me to patch them with a hot mix resin(edited to read HOT MIX GELCOAT) patch. I will wet and dry these down flat tomorrow and prep both* molds for part production.

The molds I have now are glass stand mounted for ease of working with and do not have the beading lip/edge that the original efforts had.

Another couple of days and I hope to have some parts.

Cheers,

Mitch.

[Mitch]

FAILURES and FRUSTRATION.

G'Day Gents,

Very important you use a wax that is compatabile with your PVA.
AND make sure the wax is silicone free.

I have been very heavy handed in waxing ON and not as attentive to waxing OFF, it seems if the wax builds up, then this area will most likely be subject to failure.

Also, if the Gelcoat takes to long to go 'off' then apparently the catalyst (MEKP) can have time to eat into the WAX. It should not be able to go through the PVA but then you must be sure the PVA has fully covered the part. If there is excessive build up of wax and or it is green (not fully dried) then the PVA may noit go on effectively and a resultant welding of the gelcoat to the mould may be the result.

Do not use wax paper coffee cups as mixing cups. This can cause contamination. (Yet I am at a loss as to why 95% of the instrument pod part shown has such a good gelcoat finish.) Anyway, use plastic containers as mixing cups.

Everything needs to be very clean all the time, reduce dust and lint and other contaminates to ensure best practice.

I will be trying a high grade Nu-Cerawax this week and the trick is to be very light handed with the application. Dont try and put too much on (over engineer your safety margin) and make sure you polish it off. Several applications of clockwise and counterclockwise will do nicely. Make sure you have plenty of clean lint free cloth and turn cloth regularly so as not to reapply what you just wiped off.

This process has been my archielles heel. This pod would have been a very accepatable part had it not welded into the bottom of the mould due to excessive wax build up in this area, which even though left to dry for one hour after the last coat was apparently still 'green', resulting in a failure and more frustration.

The instrument panel had two small weld spots at each end, this could have been repaired with a hot mix of black gelcoat BUT it has been sent off to Western Australia. Peter Barsden has kindly offered to 'eye ball' the part determine cause of dulling (around the edges near the radiused lip)and streaks on the part and left on the mould after layup.

I am told by two other pilots who have seen this failed pod part, that the part and the gelcoat is very acceptable. It would seem that once Pete determines exactly what's happening, that I am not far off turning out something half decent.

Many websites are helpfull in getting started BUT they do not give the fine detail info required to get over some of the problems that arise. Also, never rely on a sales rep (so called expert on the product) as their information and recommendations are often WRONG!
Ask a rep if their gelcoat is ISO or ORTHO based and see what kind of response you get.

What a fantastic thing it is to have an Asst Tech Mangager who will take as much time as Pete has with me and my project. Cheers Mate.

Mitch.

[Mitch]

And Pod pics.

[Mitch]

I had to decide to save the mould or the part. When the pod gelcoat fractured during the removal I cut the part out of the mould and have only to redress some small blemishes on the mold before it can be used again.

I am waiting till I get the new high grade wax and Pete Barsden is sending me back a new mold and part with new advice (after eyeballing my part), before I proceed.

Happy to take a little break from this. :paper: More info required.

Mitch.

[Sonnyj]

Mitch
Well done,seems youv'e been working your fingers to the bone here.
It is a learning experance aint it?
Keep "pluggin" away at it mate, you'll get it. :peace:
Cheers Cobba
Sonny

[BeefBear]

Mitch,

When do you get your "Masters" in Fibreglassing?

Ted

[Mitch]

Gents,

Having some success now, with product I am almost happy with. I will be using this new article to sort out some minor blemishes and to reshape slightly for a more professional product. Otherwise the finish came up 'mickey mouse' spraying the PVA on and as you can see it transfered from the mould to the article (on the pod), which is exactly as it should be.
Thanks to all who gave me advice and helped along the way.

Mitch.

[Mitch]

More Pics

Mitch

[Mitch]

And again

[rotor]

Mitch,

Looks like all the hard work has paid off, great finish!! and it even comes shrink wrapped :eyebrow:

[Mitch]

G'Day Rotor,

See the pic of the face plate and mould...I used water to break down the PVA and it was a bugger to remove as hydrostatic suction came into play. The pod it self was separated from the mould using compressed air. I simply pinched/pressed both sides of the mould inwards slightly, which broke the bead. Inserted a thin plastic wedge, then injected a shot of air and the pod article came out clean with the "cling wrap" attached as it should. The mould has wax and PVA on it, then the article is laid up. When they come apart the PVA should transfer and stay with the article.

Yeah, real pleased with where I'm at now. A mate came over the other day and upon seeing the article, smiled and said "so you gave up and bought one eh?" I cant print my response here, but after all the hard work I'm sure you can guess.

Cheers,

Mitch.

[Sonnyj]

G'Day Mitch
Strewth, now thats the best lookin pod this side of the black stump.
Beaut mate, a fine example of fair dinkum craftsmanship.

Cheers Cobba
Sonny

[rotor]

Sonny ... it does look good doesn't it. Full points for effort Mitch* :peace:

[Sonnyj]

Yup
I think Mitch realy out did himselfon this one. :peace: :friday:

Howz my Oz slang comin along?
Sonny

[rotor]

Oz slang ...


great mate :peace:

[Mitch]

Sonny,

Your Aussie slang is comming along in leaps and bounds. Will I be seeing you at Biggenden in 2006. Would blow me away to catch up again Dude. This time we have to get a 'jam' happening.

PVA TO SPRAY OR NOT TO SPRAY.

It seems some folk never use PVA as a backup release agent when doing fibreglass work, prefering wax only. Others, after inittially waxing up a new mould and going through the breaking in process, will then delete the waxing from the equation and just use PVA.
Then there are those folk who use wax and PVA combo as part release agents.

PVA can be wiped, brushed and sprayed on. I must confess I have had no success with wiping the PVA on and brushing left less than satisfactory results. Spraying also has its drawbacks until such time as one acquires the right skill set to apply correctly. I am sure the same is true for wiping it on with a cloth. Since I have got the spraying thing happening pretty good now, I'd like to explain some processess that may help others.

Most stuff I read suggests the proper course is three coats of PVA on a previously waxed mould.

A DVD sent to me by Dave B goes like this. (This guy uses the PVA only and doesn't worry about waxing at all). The first two are mist coats. Turning up the flow rate slightly for the second coat. Again for the third coat the flow rate is increased and a slight orange peel effect is required. Sounds crazy but wait. As it dries (mist coats 15 mins wet coat give an hour to be sure) the PVA skin stretches tight covering any blemishes.

I tried this process and one of the problems that can occurr is that the PVA may pick up dust or pick up on itself and congeal, throwing little flecks against your mould. This usually will happen on the third coat and is a real pain in the neck as one then needs to wash this off and start all over.

FRP Pools and Spa's in Tassie wax their moulds, then turn out up to 70 or 80 parts before having to wax again. They deleted the PVA from the process due to the same problem I discussed above. This a large industrial application and they needed to purchase a $20,000 filter system to eliminate or reduce said problem. They chose not to. All their product is 'mechanically' worked after release from the mould.

I was advised by friends in the US that after waxing one mist coat only is reqired and the client will wash the PVA off the product.
I was further told if I was peeling off the PVA like glad wrap or a snake skin, then I was using to much PVA. Yet, many sites (composite product suppliers) recommend this wet coat process and advocate that the PVA should depart the mould and end up on the part.

So, many experts and lots of advice.

My experience is this.

Spraying PVA can result in most excellent finishes that require no further 'mechanical' working and provide a gloss or satin finish.

PVA (Poly Vinyl Alcohol) should be sprayed at 60 plus psi some suggest between 80 and 100psi. I like 70-80psi. You are looking for high pressure low volume.

This means low volume. So when you first start shut your gun right down so that the fine mist that is sprayed is almost invisible. Now give one quick coat staying a good 400mm - 500mm from the product. This will give you an overspray type effect, barely visible.

Second coat 1/4 turn on the volume. Repeat. 15 mins is usually all that is required between mist coats.

Third coat another 1/4 to 1/2 turn on the volume knob and this time looking for a slight orange peel effect. Stay well back as suggested from the part, starting your gun before your pass and off again once passed.

I found if you leave the gun running or you are to close to the part the third coat can 'fleck' on you and fisheye and a poor wet out can result.

So dont be tempted to turn up the volume flow rate to dramatically and the results can be excellent. This results in a gloss finish. (see Pod mould)

A satin finish can be obtained by one to three mist coats depending on the texture of the satin finish required. (Face plate mould had three mist coats).

There is little danger of 'flecking' the mould during a mist coating and an article requires no further mechanical working. The same is true for a gloss finish once the spray technique is in hand.

Ensure two moisture traps are installed and clear them before and after each coat, to reduce the likelyhood of moisture droplets causing the flecking.

Please note that these are moulds and as such will require processess to season and break them in. The photos are only intended to give you an idea as to the possible finishes for the final articles. Further note that neither mould has been mechanically worked. The only treatment was a quick wash with a warm soapy flannel to wipe the PVA from them. That's It!

I have found this process the most fool proof for me.

The last three months has been a rather interesting learning curve. I would like to thank everyone who helped me with this process. Larry Neal and his glassman Bernie (in the USA), Dave B (ex Victoria) for sending the DVD and to Peter Barsden who, as always, is willing to help with advice or hands on help.

Mitch.

[BeefBear]

I can feel a shine coming on....." Looks terrific Mitch Great decription of the process.

Ted

[rotor]

It's all in the preparation - the end result that is. All bulls$#t aside,* you've done a great job !!! You've got a lot more patience than me mate.

Time to celebrate* :friday:


rotor

[Sonnyj]

Hey Mitch
They say, every dog's got his day, but a good dog has two. :pistoles:
I'd say you got at least THREE comein to ya for this!!!!!!!!!!! :peace:
Thanx the call Cobba. :cheers:
Sonny

[Mitch]

G'Day Gents,

Been flat stick with the house lately and the Master Builder is gone, replaced by a less pretentious builder with more CDF and very productive. Pics where we are at now. Raining today so may get some time in on the Blue Butterfly.

Producing face plates and instrument pods now, that have ample room for trim and the latest in Royal Blue is close to the Baltic Blue of the gyro frame.

Will be taking some to Biggenden for display/sale.

Next job is to lay-up some new skins for my AirCommand Tail rebuild.

Fly Safe,

Mitch.

[Mitch]

Couple More Pics.