chainsaw repair - anti-vibration mount unglued

[graham]

I have a small Jonsered chain saw that has worked very well for me - it's only been for light work - until a number of years ago when the anti-vibration mount became unglued at the joint between the metal and the rubber. This is the mount on the left hand side and while the rubber end appears to be just screwed into the handle the metal end is tightly gripped into the mounting on the body (I should add that I've not used many chainsaws so I don't know exactly how standard the fitting is). Bearing in mind its age etc. I decided to have a go at re-gluing and, after a little trial and error, have found a glue that more or less works but the 'less' part is that is seem to survive for a year or so only but almost regardless of the work done, but then a re-glue and it's fine again.

I had the use the saw a few days ago, and it started first time despite not touching it for over twelve months, and while it did the necessary on the branch that had fallen in the road the mounting failed just at the last moment.

Two questions: can one buy replacement mountings ? And does anyone know a really good metal - rubber glue ? As I mentioned I have found one that just about works but if one knows of a really reliable glue I'd be interested

graham

[Wendelspanswick]

http://www.loctitehf.com/assets/tds/480-EN.pdf

Engine mounts for my car (a 1939 Austin Big 7) are no longer available so I made my own using the above. Be careful where you buy it from as some companies charge silly money.
Try eBay.

[Toby Allen]

You should be able to get a replacement from a decent chainsaw or garden machinery dealer. They have all the parts on a computer ordering system.

I would recommend against fixing it again with glue unless you really have to. The AV mounts are a safety feature, having nerve pain or white finger is bit annoying.

[graham]

so I made my own using the above

I did note the comment "Optimal Storage: 2 °C to 8 °C. Storage below 2 °C or greater than 8 °C can adversely affect product properties." which does seem a little restrictive!

You should be able to get a replacement from a decent chainsaw or garden machinery dealer. They have all the parts on a computer ordering system.

How does one extract them ? It appears to be rather tightly gripped by bits of the aluminium body - not a material that is readily workable I would have thought.

The AV mounts are a safety feature, having nerve pain or white finger is bit annoying.

It's not really an issue: the machine is not usable without the mount complete - the handle is otherwise only attached on the right hand side, in fact even less vibration but certainly not usable

graham

[Wendelspanswick]

These adhesives are developed for the aerospace industry and the like so for optimal performance of the adhesive it needs to be stored at the correct temperature but I have to say that even though I have no idea if the correct storage procedure was used on the glue I purchased the engine mounts have been on the car for 2 years which has been used extensively for hill climbing without sign of failure.
I used to work for a company that made items for the aerospace industry, the Military and formula one teams from high tech polymers and every thing had a shelf life. When that date expired all the materials would be skipped, the amount of surfboards, boats, canoes, skateboards, bicycles, motorcycle parts etc. produced out of hours from those out of date materials was astonishing!!!

[graham]

Just an update - I did get the loctite 480 a couple of weeks after the post and glued up the joint fairly soon - must have been in February and the saw has been sitting quietly since.

I went to use it today, in fact just to shorten a couple of fencing post, and the joint survived, oooh, two seconds.

I was quite careful, cleaned the surfaces of old adhesive, and then with alcohol to remove any oils, allowed to dry etc.; applied the adhesive and tied the joint up - although it's supposed to set very quickly I thought it worthwhile to leave alone to cure. I left it like that for some days, mainly because it was out of the way and then took off the binding and it's been sitting untouched since.

So - back to the Lidl glue, which seemed to work for a few months at least.

graham

[Wendelspanswick]

That's a shame, I have recommended Loctite 480 to a few people with great success and yours is the first failure I have heard of. Perhaps there is a design flaw or other fault that is loading the mounts more than usual?
Rereading your original post you say the anti vibe mounts are rubber and metal, I assumed the metal would be steel but now I am wondering if they are aluminium? All my experience of 480 is with rubber and steel.

[graham]

Perhaps there is a design flaw or other fault that is loading the mounts more than usual?

I doubt that - it's only a small saw and I start it by standing on it, so to speak, and pulling the cord; it's too light to throw it and pull the cord so that when I did start it I wasn't even touching the handle at all.

assumed the metal would be steel but now I am wondering if they are aluminium? All my experience of 480 is with rubber and steel.

That's a good point - I must admit I assumed that it was steel, it certainly is a separate component from the aluminum chassis. I've just cleaned it up and had a close look but it is difficult to be sure with a small area, and I don't have any magnets to hand... The metal is quite hard, it doesn't mark when given a good scrubbing with a wire brush which i would expect to mark aluminium. What I did notice is that while the adhesive is well bonded to the rubber side there was no sign whatsoever on the metal - it just came away completely clean.

graham

[Dexter's Shed]

is the steel/ali hollow or thick enough to drill a few small holes in, then screw in small self tapper screws, to give the glue something to hold onto?