What would you want to know first?

[old man emu]

Consider this scenario:

 

You've decided to build a kit plane; have made the purchase, and all the bits and pieces have just been delivered to your workshop. Like a kid with his first Airfix kit, you have unrolled the plans on the lounge-room floor and are studying them with unbridled excitement.

 

If it you had a Guardian LAME whose task it was to guide you through the many stages of a successful construction, what would you want to know first?

 

I pose this question to learn what areas of aircraft construction people would appreciate getting assistance.

 

Old Man Emu

 

 

[Yenn]

Where have others come unstuck, where are the pitfalls, what can I stuff up?

 

 

[Ultralights]

is every part identified in the kit? and is every part as described in the plans/manual.

 

 

[old man emu]

Yenn,

 

Your reply is along the lines I'm thinking of, but a bit too general. Can you be more specific?

 

Ultralights,

 

After having done that, what next?

 

Old Man Emu

 

 

[Guest brentc]

My principle was 80% research, 20% doing.

 

It seemed to work well for me. I use that for work and for play.

 

Measure 4 times and cut once.

 

 

[old man emu]

Brentc,

 

I agree with your comment, but WHAT PART of the construction would you want to be able to ask about --- jigging a frame; welding a frame; fabric work, or maybe rigging the aircraft?

 

Old Man Emu

 

 

[Guest brentc]

For me, at first I needed to know about fibreglass - mixing it, mixing in fibre-flock, how long till it sets and when I can sand it.

 

 

[Ross]

My problems were similar.

 

Mixing resin & hardener was my initial problem and the speed and nature of curing.

 

Some experiences during my build which is not passed by a LAME yet.

 

Purchased an old set of post office letter scales w/o weights maybe about 1 Kg or 2 lbs limit capacity for weighing out resin and hardner.

 

Bought 48 of 5/16" shiny nuts to use as units of mass for the balance.

 

3 nuts of resin and one nut of hardner by mass.

 

(3 to 1, or 6 to 2, or 9 to 3, or 12 to 4 etc)

 

Using nuts any larger than 5/16" as units of mass would result in too much loss of epoxy when doing the many small jobs that are involved like attaching three alileron hinges or attacjing the control stick limit.

 

Bought extra mixing containers 100 at a time like the Jabiru supplied ones from the local wholesale shop

 

Bought boxes of medicine measuring containers from a local chemist - they come in packets of 50.

 

Bought paddle pop sticks (craft sticks) from the wholesale shop.

 

Bought a combination electronic temp, relative humidity. and clock instrument to record those parameters until jobs are cured. I generally recorded parameters hourly up till midnight trying to make sure that application of epoxy and assembly was completed by about 16:00 hrs. It also recorded min and max.

 

So far I have mixed about 130 separate batches of epoxy or epoxy & flock or epoxy and microballs and a sample of each batch has been taken and allowed to cure in the medicine glass. Once cured it is numbered with permanent texta and stored in a "Honey" jar with other samples which are also labelled with the number and description of where they were used. This is also recorded in the constuctors log book.

 

Bought bulk acetone in 20 litre containers (on my third 20 litre container)

 

Bought a paint scraper with a carbide blade a bit like an enlarged version of a single blade shaving razor.

 

My experience of curing is only in the assembly of a Jabiru kit is that it proceeds at any temp above about 16 degrees C but more slowly as the temp drops closer to 16. At 16 C it would probably be more than 12 hours maybe 24 before the job was safe to support itself.

 

Twenty five degrees C is pretty good for the type of epoxy jobs on assembling a Jabiru Kit giving time to do a number of mixes and assemblies before it cures.

 

Large batches will get very hot and will accelerate the curing making it difficult to complete before the mix becomes unuseable.

 

High temperatures like 30 degrees C plus speed up the curing and are good after the initial assembly of parts and application of epoxy.

 

Interrupted curing by low temperatures will continue once the temperature rises again.

 

I really noticed it this summer after a cold winter that the partly constructed J160 gave off quite strong fumes once we had a few very hot days which has since virtually stopped except for new work. My garage has had a few days over 40 degrees C which is pretty good for developing full strength curing but it needs the time to do so.

 

I purchased a paint stripping gun which I found very effective for adjusting or stress relieving after curing especially of items like hinges.

 

The paint stripper gun (hot air gun) is also very useful for disassembling parts that need to be moved or modified.

 

The curing process is a chemical reaction that depends on the mixing of the correct ratio of the components ie resin and hardner.

 

 

 

Mixing the components not in the correct ratio will result in an unpredictably lower strength of material.

 

 

 

 

 

[Yenn]

Old Man Emu.

 

That is what I would want to know, but the trouble is where to find the info. In my case I built a Corby Starlet and there is a great newsletter published in the USA.

 

It covers just about anything you need to know, except 1 item which I had to re make as it wasn't clear in the drgs.

 

There is a wealth of info on the web. Just Google the aircraft name and go from there. Talk to anyone in aviation and they will know a friend of a friend who knows what you need.

 

A great place for info is Kitplanes magazine, also look at the RV website and Chris Heintz site,and "homebuiltairplanes.com" also worth a look.

 

If all that fails, just ask on this forum.

 

 

[Downunder]

What about an online forum (on that particular aircraft) where you can research others mistakes and ask questions yourself?

 

 

[Admin]

Guys

 

The other day in one of my shipments from the US I received for the shop 50 copies of a basic guide to epoxy systems that will be free other then the shipping cost of $1.75.

 

The subjects covered are:

 

Handling Epoxy:

 

Safety, Cleanup

 

Epoxy chemistry

 

Dispensing and mixing

 

Adding fillers and additives

 

Basic Techniques:

 

Surface preparation

 

Bonding (gluing)

 

Bonding with fillets

 

Bonding fasteners and hardware

 

Fairing

 

Applying woven cloth and tape

 

Epoxy barrier coating

 

Final surface preparation

 

Finish coatings

 

Problem solver

 

As I said they are free booklets that will be available from the shop except for the shipping cost - I hope these will help some people.

 

Also, there is a big surprise coming soon to help ALL kit builders - mums the word at the moment but will let you know when it is all ready

 

 

[Ross]

Hi Ian

 

Put me down for one please. But I am afraid I might have to start again.

 

Regards

 

 

[BigPete]

Me too - please. Perhaps you can bring some to the fly in.

 

regards

 

 

[Ultralights]

a little unknown fact is that Sunlight, or more specifically UV will aid in the curing of some of the more common epoxy resin systems..

 

 

[Galpin]

50 copies of a basic guide to epoxy systems

 

Put me down for one as well, Ian.

 

Thanks

 

(Looking "forward" to the surprise)

 

 

[Deskpilot]

Me to, please, Ian. I'll pm you my address.

 

BTW, did you receive my pm ref My Photo Gallery?

 

 

[icebob]

me too please Ian

 

 

[robinsm]

I'll take one.

 

Cheers

 

Maynard