Cessna 152 Aerobat

[Richie Carey Maddog Designs UK]

I use this technique for butt jointed panels. If the panels you are trying to reproduce are overlapped, you can use the same technique using wider pin striping but only apply the body filler to one side this will give you the appearance of a raised panel.

[Richie Carey Maddog Designs UK]

And yet more sanding with wet and dry (wet) sand the body filler back until you can just see the vinyl pin striping, now feather the edges of the body filler so that they blend in to the cowl.

Carefully remove all of the pin striping and the vinyl

Next apply another coat of white primer, this will show up any areas the may require further feathering, once you are happy with the cowl apply a final coat of white primer.

Next will be rivets and screws and then final painting.

[Tony F]

Master class....lovely work and great to watch / learn.

Tony

[Richie Carey Maddog Designs UK]

Thanks Tony,

I had some good teachers when I fist started modelling, that’s what I love about this hobby, the willingness to share knowledge. Back in the day the old boys were always happy to help and give advice to us novices and now I’m an old boy it’s only right that I pass their expertise on to the youngsters of today, after all its not my knowledge, I only borrowed it for a while.

If this thread encourages just one modeller to have a go at designing their own model, its job done.

Richie

[Former Member]

[This posting has been removed]

[john stones 1 - Moderator]

Impressive stuff Richie

Not something I've ever done, yet

John

[Richie Carey Maddog Designs UK]

On with the fasteners, I have decided not to add rivets because 1 this is a stand off scale model and two you would have to get really close up to the model to see them so they are not required.

Ok, first mark the position of the fasteners on the cowl.

Using a small grinding tool make a dent in the cowl, this is to replicate the dent created when fasteners or rivets are punched into a metal skin.

My apologies for the poor quality photos but hopefully you can get the idea of what I am tying to achieve.

Mix a small amount of 30 min epoxy and put it into a small syringe.

Place a small blob of epoxy into each dent.

When the epoxy is no longer sticky to the touch but has not full cured use a piece of brass tube sharpened at one end to form a circle by gently pushing it into the epoxy.

Next using a small flat head screwdriver gently push it in to the epoxy this will complete the screw head.

When the epoxy has cured you can now sand it almost flat using 800 grade wet and dry (used dry).

Now if you want to try this, I suggest that you do some practicing first and the more effort you put in the better the results. This is time consuming but the end result is well worth it.

[AVC]

Excellent job, and excellent approach to share your knoledge and experience with us the youngsters (I'm 42 BTW..).

Thanks, and please keep posting!

[Richie Carey Maddog Designs UK]

Thanks Alejandro I’m sure that when you are an old 54 like me you will pass on the wealth of knowledge you pick up over the years.

The Cessna is on hold over the weekend due to an unexpected visit from an old friend we don’t see to often up here in the frozen north east of England ‘the sun’ so its play time for me.

Take care everyone normal posts will resume on Monday.

Richie

[AVC]

Hey, I also live in the North East, in Boldon Colliery, near Newcastle. In the summer of 2012 I decided to change the boring weather in the south of Spain for this much more interesting weather in the North East of England. And so far, so good...

[Andrew Price 2]

Hi Alejandro. Blimey, I'm 68yo!! Am I allowed to follow these posts?? Andrew (Confused and possibly passed it)!!

[john stones 1 - Moderator]

Put some suncream on your head Richie

John

[Richie Carey Maddog Designs UK]

Boldon Colliery, that’s just down the road from me, well through the Tyne tunnel and down the A19 a bit lol

Andrew everyone is welcome young man.

John there is no need for sun cream, my head is so shiny the sun rays just reflect off it.

Richie

[Richie Carey Maddog Designs UK]

Whoopee….. I have managed to get a close-up of the fastener, just two coats of paint to apply which I will do on Monday then I can start making the polyester mould.

Richie

Edited By Richie Carey Maddog Designs UK on 17/05/2014 12:54:15

[Richie Carey Maddog Designs UK]

I got bored so I decided to finish painting the cowl and I have surprised myself because for the first time ever I have actually sprayed something and there is no orange peal effect so I don’t need to use any rubbing compound. Well that’s the cowl plug competed, next job is making a polyester mould.

[Richie Carey Maddog Designs UK]

Here we go building the split mould frame, start by covering the entire cowl plug with cling film, now measure the cowl base where the mould is to be split.

Transfer the measurement onto a piece of cardboard and draw a line between the marks.

Now use a piece of electrical cable to mould the shape of the cowl, place the cable onto the cardboard and draw the shape of the cowl onto the cardboard and cut it out. Check the fit of the cardboard cut out on the cowl, when you are happy with the fit put it to one side.

Next is a trip to B&Q to pickup the materials required to build the split mould frame.

Pack of screws

Pack of nuts and bolts

And a piece of ½” Formica particleboard (I got two pieces from the off cut section in B&Q for £1)

Cut the Formica into the required parts.

Using the cardboard cut out you made earlier transfer the cut out onto the Formica and cut out with a jigsaw.

You will need to cut a base a centre section and two side supports.

Now put the frame parts to one side, remove all of the cling film and start waxing the cowl plug, you will need to apply a minimum of 7 coats and allow 45 mins before buffing up with a soft cloth between coats. I don’t use release agent as I find I can achieve a better finish with mirror glaze wax.

[Richie Carey Maddog Designs UK]

Apply a strip of plasticine around the bottom of the cowl and screw the cowl plug to the base, this will compress the plasticine, now remove the excess plasticine.

Screw the centre section in place followed by the side supports.

[Tony Bennett]

getting curious about how this is going to work.

[Richie Carey Maddog Designs UK]

Yeah me too sir hahaha.

Well we are getting closer to laying up the first half of the split mould but first we need to do the prep work for the gel coat. Start by cutting some plasticine into thin strips, this is used to seal the gap between the cowl plug and the centre section.

Next place a light under the split mould frame so that it highlight the gap you need to fill.

Using a piece of dowel sanded flat at one end remove the excess plasticine.

I find the best way to do this is to push down firmly with the dowel then pull back sharply in one motion, this will pack the plasticine into the gap and remove the excess in one go. Though it does take little practice to get it right.

Use the light to check that you have filled all of the gaps then remove all unwanted debris from the frame and cowl plug.

Now apply another three coats of wax to both the cowl plug and the split mould frame, again leave 45mins before buffing with a soft cloth (make sure you don’t leave any wax that will clog up the panel lines).

[Martin Harris - Moderator]

Posted by Tony Bennett on 19/05/2014 20:00:08:

getting curious about how this is going to work.

If I'm following this correctly Richie, I'm assuming you've allowed for the width of the centre section and will make a half mould, then reposition the plug to make the other half in the same way?

Edited By Martin Harris on 20/05/2014 12:48:26

[Richie Carey Maddog Designs UK]

Hi Martin,

There is no need to allow for the width of the centres section, the only reason I use ½” particleboard is because it make a solid frame. The trick is to ensure that the front face of the centre section is in line with the centre line of the cowl. Once the fist side of the mould has been formed and cured, I will remove the centre section and the two side supports then lay-up the second half of the split mould directly on to the first half, the cowl and the first half of the split mould remain in place throughout the laying-up of the second half. I hope this helps, if not all will be revealed in due course.

Richie

[Richie Carey Maddog Designs UK]

Gather together the items required to apply the gel-coat.

Polyester Gel-coat and hardener

Measuring tub (for the gel-coat)

Syringe (for measuring the correct amount of hardener)

Old spaghetti hoops can (if you don’t have a spaghetti hoops can any old can will do)

Mixing sticks

Sponge brush (for applying the gel-coat)

Latex gloves

Old mixing board (as you can see mine has been well used)

Pour the required amount of Polyester gel-coat into the measuring tub 100ml should do for this size cowl, now pour it in to the old can.

Use a syringe to measure 2ml of hardener and add this to the can. Mix for about 2mins to ensure it is well mixed.

Apply an even coat of gel over the mould frame and cowl by brushing in one direction only until they are completely covered try to avoid using an up and down brushing action.

Next you will need to cut some surface tissue and chopped mat into approximately 2” by 8” strips ready for laying up.

[Richie Carey Maddog Designs UK]

Mix up a batch of polyester resin 100ml add 2ml of hardener.

Cover the gel coat with the polyester resin.

Now use the surface tissue you cut earlier and apply one layer over the gel coat using a stipple motion, don’t be tempted to use brush strokes as this will just pull the fibres apart.

Once it is covered leave it to cure for about an hour.

Mix up some more resin (you will need about 300 to 400mil of resin to apply the chopped mat, I always mix the resin in batches of 100ml this means that the resin you are using is always fresh) and apply two layers of chopped mat making sure it is toughly wetted and there are no air bubbles trapped anywhere.

Once all of the chopped mat has been applied leave it over night to completely cure.

[Tony Bennett]

wow looks good.

learning lots from this thread sir, keep it up.

[Ton van Munsteren]

Thats very nice work, keep posting those great pics.

Ton