Light Aircraft Association

Hi all, bit of advice needed pls.
What glue are people using in the UK for woodwork, eg. wing ribs etc. The EAA vidoes I have watched all seem to use T-88 but that doesnt seem to be very available in the UK. I visited LAS in Okehampton yesterday and they suggested Aerodux 500 (Prefere 4050). Looking into this I can see that the Aerodux 500 is a resorcinal glue which would require a much higher standard of fitting and higher clamping pressures. I like the idea of T-88 due to the fact that this will be my first aircraft build and I dont have a massive amount of wood working experience, so the gap filling and lower pressure of T-88 might just be a bit more suited to me. Is there a UK equivilent of T-88 or similar expoxy wood glue available in the UK. Another advantage of T-88 as far as I can see would be easy mixing of 50/50 by weight so more suitable for a lot of small amounts made up, eg 1 rib at a time. Any ideas would be greatfully received

T-88 is available from Aircraft Spruce in the USA and can be ordered from LAS as their UK agents. Try putting Aircraft Spruce product code of 02-00047 into the LAS search facility - it shows that they have none available in Devon but can obtain it from their supplier in 5-7 days.

Aerodux 500 (Prefere 4050) is my preference for laminations and most other applications. My test pieces have always passed easily, even with simple spring clamp pressure.

There has to be firm contact between the parts and a close fit is always desirable, but my impression ( and I have only information gleaned from my experience so far and from my reading to go by - no technical expertise!) is that the Aerodux resorcinol/phenol formaldehyde glue is not as critical and doesn't require the extreme precision and clamping pressures needed for older resorcinol glues. I am always finicky about preparing and cleaning the wood surfaces - and maintain minimum curing times and temperatures before releasing modest but firm clamping pressure.

I'd be interested to hear ( & learn ) more.

I've had good experience (so far) with Aerodux (aka Prefere) recorsinol glue on my Menestrel. I concur with the comment that as long as the gap is reasonably close it works fine with spring or temporary staple pressure. It has been used extensively for the DH88 Comet Racer "Black Magic" rebuild at Derby airfield. The only issue I've had is breaking the test pieces before they've reached full strength but leaving them to cure properly the test pieces fail in the wood, not the glue. You can get the glue from LAS in Devon (they'll post it no problem).

Tony Razzell

Would suggest a read of Dudly Patersons article in the recent LAA magazine.

He covers the two glues popular and available in the UK.

Ian Melville wrote:Would suggest a read of Dudly Patersons article in the recent LAA magazine.

He covers the two glues popular and available in the UK.

Thanks for that, which month was this please

Check that T88 is approved by LAA before you use it.

Woodsy wrote:Thanks for that, which month was this please

Glad that was brought up .
I remember reading Dudley's excellent article on woods/glues and was going to give it a mention myself , except I cannot for the life of me remember which months LA mag it was . Dudley mentioned both Aerodux and Aerolite-306 . Aerolite was what I used exclusively when building mine and it is completely odourless , very user friendly regarding 'shuffle times' and has good crack filling properties .

But Ian has an extremely efficient filing system for his LA magazines , I'm sure he will find the right the right one ......

It was in the November issue. If anybody no longer has the mag, drop me an email and I'll send you a pdf.
Rgds, Brian.

Hi,

West Epoxy is the T-88 alternative most widely available in the UK.

I have never used Aerolite but other people do great work with it. I have always previously used Prefere (Aerodux) and as Tony said we are using gallons of it on the Comet, but have recently been using West Epoxy on two personal projects, one a new build and the other a repair.

The only aircraft I know where epoxy is specified is the Minimax which I understand relies on the filleting effect of epoxy in some joints - but that may be hearsay.

Others may disagree, I but I think West Epoxy is really good and is the way forward. It is widely used in the boat building world and has an established history. It is freely available from many chandlers but I buy it mail order from Axminster Power Tools:

https://www.axminster.co.uk/west-system ... ck-ax22120

West do offer mixing pumps but you don't need them for the volumes used in an aircraft glue up. It is not difficult to mix even tiny batches of 5:1 resin/hardener by weight. I use what I call 'drug dealers' electronic scales and mix in small plastic medicine cups. You can choose to add a filler if necessary. There are fast and slow hardeners available, I like slow.

The glue process I use is to coat both surfaces and allow it to soak in to the wood for a few minutes, lightly re-coat one or both surfaces, bring together and clamp. Where filler is considered helpful or a fillet is required then a small amount (I use West's colloidal silica) gets mixed into the leftover glue to make a suitable paste after the surfaces have been coated with the original mix, and that is used for that final application. Any excess and run out is best dealt with before it sets rock hard. Clamping pressure seems non-critical.

Having made, broken and examined many test samples I believe I get much deeper penetration into the wood with the epoxy than is achieved using Aerodux and more wood remains attached to the glue line when the sample is broken. The situation on wood to ply joints is a bit different as the glue cannot penetrate the glue lines in the ply but it certainly goes to it.

There are some drawbacks to each system. You can get sensitised to both Aerodux and Epoxy so wear gloves when handling both and don't breath in the vapours (Aerodux seems particularly noxious - read the documentation). Epoxy is sensitive to high temperature and any significant volume left in the pot can get smoking hot on days like we had in the summer. Also, the glue strength is weakened at high ambient temperatures, so my approval to use it from Engineering was given subject to not painting the air frame in dark colours. Having said that, our American friends tend to get more extreme temperatures than we do and use it freely. Aerodux is very messy, Aerolite is very clean. Aerolite has a longer pot life than either alternative so less haste and less waste. I believe that Aerolite can add to 'starved horse look' on ply surfaces but can't support that from my own experience.

For lamination work I would always turn to Aerodux even though I cannot imagine a messier way of working! Spring back of laminated parts is negligible.

Frankly, any of these three glues does a good job when handled correctly. Thorough mixing of the two parts of epoxy and Aerodux is of prime importance.

Anyway, this is just my opinion and if you want to use epoxy you will need to get the support and advice of your inspector as he needs to be comfortable with it, and do talk to Engineering as I don't think it has the blanket approval of the other two glues.

Where are you - is one of Dudley's courses appropriate?

regards,

Colin

I have also used small amounts of West epoxy and like it, but have only needed to use it for small non critical areas. I have been using the West pumps and find this a chore, so will give the electronic scales a try. That sounds like the best option and by coincidence, I was about to look for suitable scales as an alternative to mixing other things by volume.