Huon Pine and CA glue

[berocol]

Hi pen makers

I've been away from the Forums for a while but thought you guys might be the best people to ask about this.

I've made a few pens over the last few years, mostly using Slimline kits - some in wood and some in acrylic. The wooden ones I've mostly finished with CA glue, with generally good results on various woods.

Before Christmas I made one in Huon Pine, and finished it with multiple coats of CA. During the process of assembling it I noticed small cracks in the surface around where the nib presses in. OK, thought I, the tube's a bit undersize or maybe I didn't clean it out inside properly. Over the next week or so it cracked lot more on both top and bottom halves, and with both radial and longitudinal cracks. I would say it is crazed. I've attached a pic - you can see some of the cracks.

I have to confess that the CA glue I used (from Timberbits or a similar supplier, not the $2 shop) was a bit old and had thickened up in the bottle, so I put it down to that. However I showed it to another woodie yesterday and he said that it was well known in his group that Huon Pine and CA did not play well together because of the oil content in the timber. I hadn't heard that before, and neither have the guys at my woodturning group today.

Has anyone else had trouble with Huon Pine and CA glue, or is it more likely that the problem was with the old CA?

I'd appreciate any comments.

regards, Colin

[China]

Huon Pine can play havoc with lots of finishes due to the natural oil content so I think it is most likely the timber rather than the CA

[Skew ChiDAMN!!]

I second the problem being the oil content.

Next time, try wiping the timber down with acetone almost immediately before applying the CA. Similarly, you should flush the blank with acetone immediately prior to gluing in the tube. (Or a similar quick drying, zero deposit thinner. Metho will do, but IMO acetone is best.)

This is true for all oily timbers... such as teak, merbau, whatever.

It only temporarily removes the oils from just under the surface, giving the glue/finish time to adhere better before it seeps back..

[dai sensei]

Huon can have issues due to oil as mentioned above, but cracks at ends is often caused by CA inside the tube not being cleaned out properly, so the nib is too tight in the tube.

[Treecycle]

Oil in the Huon might stop the adhesion of the CA but I wouldn't have thought it would cause any of the cracking shown in the photo. Normally lack of adhesion shows up as a cloudy appearance under the CA such as when you press in a component and the fit is too tight which causes the CA to separate from the wood. The photo shows no sign of this.

[BamBam53]

I have had the CA on a couple of pens crack recently. I put it down to the old CA I was using. It was a year old.

The barrel on the left cracked before it could be pressed together. No problems since I switched to a new bottle.

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I have not had any problems with CA on Huon Pine. This pen is two years old and still looks ok. I wipe all my barrels with lacquer thinner before a first coat of boiled linseed oil, then CA.

431528

Michael

[berocol]

Thank you gents for your comments.

I definitely think the cracks in the nib end, which I saw as soon as I put it together, were most likely due to my not cleaning out the inside of the tubes properly, but that doesn't explain the rest of the cracking which developed over the following week or so.

In the next couple of days I plan to turn the barrels for another Huon and CA pen, using reasonably fresh CA, and see what happens. I'll let you know how it goes.

cheers, Colin

[Penpal]

431628I have never treated Huon Pine differently in preparation to finishing. Most all my blanks are not the least newly milled with very little smell. I know this timber contains something that enables the tree to withstand great age and insects.

I enclose a pen also Slimline with Streamline centre band probably ten years old still looks same as with Two coats of CA.

Peter.

[berocol]

Progress report - pic shows two sets of slimline barrels in Huon Pine, sanded to 400 and coated with 20 coats of reasonably fresh thin CA. They are still on the mandrels awaiting polishing with micromesh and Brasso. No Cracks, so it would seem no reaction between the huon and this lot of CA.

cheers, Colin

431669

[Robson Valley]

No resin ducts! Much to my amazement for a conifer.

Huon Pine | The Wood Database - Lumber Identification (Softwood) (http://www.wood-database.com/huon-pine/)

[Penpal]

Many years ago CSIRO here in Canberra used the extraction (it was freely available to the public) as a Pheremone attractant for insects,then the bad news this concentrate was found to be Cancer causing and taken off the market. A mate of mine making furniture etc was forced to get out of using Huon ,he had a few ton of it in his workshop,the smell was too much for him so he onsold it.I bought a ton and a half a long time ago of the plain Huon and had it shipped from Tasmania to Canberra at a very good rate from a Mill in the West Of Tasmania during a visit there. My intention was to make toys for the Grand and G Grand children. tHe numbers grew to 50 total 23 grandchildren and the rest GG children. Our experiences were the Tom Toms beat gets around the world to our family overnight these days and they are competitive (and this includes the parents) I opted out of the exercise. The timber was offcuts at the mill where they had untold tons at that time retrieved from the water before and after a huge Dam was built.On my 70th birthday I made 27 Huon Burl Pens for the male family and Wilma Made a cloth box for the woman with a piece of her wedding dress etc in it.

Yes it does exude this oil substance but after a long time goes quite dry,the smell is retained.

Peter.

[berocol]

431798

Update on the saga of the Huon Pine / CA pens:

Both sets of barrels turned and finished and one set assembled. No cracks, so apparently no reaction between the Huon and the CA, but also not as much shine as I have previously achieved, despite using micromesh pads and Brasso as usual.

So I am going to put the cracking down to the old, gluggy CA, but I don't know why I didn't get the shine.

I might put the other set of barrels back on the mandrel and give them another 10 coats of CA and try polishing again (in my spare time).

Thanks everyone who took an interest in this minor puzzle.

cheers, Colin

[Simplicity]

Just a quick poke in.
Were you using accelerator with the CA I've had a similar issue on Huon pine and also on Olive wood.
Some have suggested it may have been the accelerator.
But I'm not 100 percent convinced yet my self either on that one.

Cheers Matt

[berocol]

Hello again pen turners

For what it's worth, another update on the CA glue investigation.

In the picture below are the second set of Huon Pine barrels, and two pens made from different pieces of Silky Oak.

The Huon and the dark Silky Oak were finished with some Mitre Fix CA which is probably 2 years old, and has also gone thick. I didn't put as much on at each coat, and it takes a long while to go off (like go and do something else after each coat) but no cracking and it polished well.

The light Silky was finished with about 20 coats of SikaBond CA - brand new from the big green and red toyshop - quite thin and went off very quickly and polished well. I think I'll keep using it and see how it goes.

To respond to Simplicity (Matt) - no accelerator, just time between coats, although I have used accelerator in the past without any ill effect.

I think I'm going to blame the cracking in the first Huon Pine pen on the old thick CA glue, put on too thick and not given enough time to go off between coats.

I know - fairly predictable in hindsight, but every so often we need these little setbacks to remind us that we are not as good as we think we are.

Thanks again to everyone who took an interest in this.

cheers, Colin



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