|Robin Graham||06/12/2018 21:55:44|
|455 forum posts|
I want to fix a bronze bush in a hole in beech wood. It won't be under much axial stress, so maybe anything would do, but as I've no experience in gluing metal to wood I'd be interested to know if there are any adhesives which are particularly good of bad for this sort of thing.
Any experiences out there?
|Jeff Dayman||06/12/2018 22:01:34|
|1303 forum posts|
If you must glue it, probably epoxy would be as good as anything. Could you put a wide flange on the insert and pass a couple of flathead wood screws through it into the wood? I really don't fully trust metal inserts glued into wood to carry any loads. I know IKEA does them by the millions daily, but if building something I try to make it more robust that that.
|Clive Hartland||06/12/2018 22:03:19|
2345 forum posts
Knurl it and squeeze it in if it has very little pressure on it.
|Derek Lane 2||06/12/2018 22:13:47|
118 forum posts
Will it get hot/warm and also will it get wet at all as both of these can effect some glues
|XD 351||06/12/2018 22:35:33|
1101 forum posts
JB weld , put a very light knurl on the outside of the bush or at least key it with coarse sandpaper or emery paper., degrease the bush with acetone or isopropyl alcohol then coat both parts with the JB and fit together . The join can only ever be as strong as the wood around it .
|not done it yet||06/12/2018 22:47:17|
|2362 forum posts|
Through or blind bush? Cross or end grain? Details do help if you want the right advice.
695 forum posts
Robin, as Clive says a straight knurl will probably do but if you want to glue it as well I would recommend Gorilla Glue, it expands while setting and is specifically made for dissimilar materials and gap filling. Epoxy does not bond well with wood but if you do want to use that type I would recommend a metal reinforced one, these do bond well to wood providing it is clean and oil free.
|Robin Graham||06/12/2018 23:02:07|
|455 forum posts|
Blimey, that was quick! This is work (as a favour) for someone who has already had the bush machined (to a convenient 21.3mm OD!), so I'm not able to redesign, though it's not how I would have done it.
I'll go with JB weld / keying the bush then - I had thought of JB , but wasn't sure if it was OK for for a close fit as its quite viscous and I worried that it might be squeezed out.
Edited By Robin Graham on 06/12/2018 23:03:31
|Robin Graham||06/12/2018 23:13:06|
|455 forum posts|
Through, cross grain. Always difficult to know where to draw the line when one's in the dark and doesn't know what the relevant details are.
4195 forum posts
As the wood expands and contracts any rigid glue will break away. Even if it has already been made I would pop it in the chuck and run a pointed tool down it in a course thread or a series of grooves and use a contact adhesive like evostick or uhu (not in contact mode) that is flexible. One problem is that bronze and brass are 'slippery' so need roughing up to get a grip.
|XD 351||06/12/2018 23:24:39|
1101 forum posts
If you want something a lttle bit thinner use araldite 24 hr . Not sure how cyanoacrylate would go on bronze and the stuff is also brittle . Ideally you want a drop in fit for epoxy so if the bush is a tight fit you may need to fettle the hole a little.
3363 forum posts
You could screw cut the outer surface and drive it into the wood
Just a thought
|61 forum posts|
Quite a few comments on the metal part (as would be expected) but the timber component is also relevant.
I am not sure how much experience you have with these so I may be doing a little preaching here.
Epoxy is fine with wood although there are as many variants of epoxy as there are of metals. If fixing to a hard wood then a nice runny epoxy (as in 24 hour Araldite or one of the specialist woodworking/boat building epoxies) would be recommended. Softwood is less critical in this regard although you are still trying to achieve good penetration of the wood fibres. Depending on the type of finish required on the wood post-gluing the extent of penetration may be an issue as it may not be compatible with some surface finishes.
Also, beware of teak and some very oily timbers as these may pose issues with adhesion. A thorough degreasing with acetone or one of the more aggressive degreasers may be required. The area will appear to be bleached but this is mostly temporary although application of the degreaser should be confined to the gluing zone.
Hope this helps
|Michael Gilligan||07/12/2018 08:37:14|
12025 forum posts
Noting that Robin mentioned beech wood [which is typically fine-grained, quite dimensionally stable, and non-oily], I would use good old Loctite anærobic retainer ... probably 601.
Edited By Michael Gilligan on 07/12/2018 08:38:22
|Adrian 2||07/12/2018 08:53:31|
|55 forum posts|
Robin, I used the knurled method many years ago on bushes pressed into the rails on the swing gear of a rocking horse.
Straight splines, quite heavy, parallel with the bore of the bush. Worked a treat no adhesive needed.
|Chris Evans 6||07/12/2018 08:55:51|
|1284 forum posts|
If going the JB weld route be very patient with curing time at this time of year. Put somewhere warmer after 6 or 8 hours and leave for a day.
|Ian S C||07/12/2018 09:27:30|
7110 forum posts
I made a pair of wheels with a 15 mm ply disc, the bush is welded to one square washer at one end, and on the other side is another square washer. All held in place by a screw in each corner of the washers, clearance on one side, tapped on the other, countersunk head, all nice and neat. The wheels have a rubber tires.
Ian S C
|Brian Wood||07/12/2018 09:27:40|
|1740 forum posts|
I have glued short ends of bar onto the end grain of softwood 3 x 2 inch battens as 'handles' using Gorilla Glue, a foaming polyurethane adhesive, which after 24 hrs of curing, allows you to saw off slices or whatever in the bandsaw
Gorilla Glue is widely available.
Because it foams you need to clamp the joint to maintain contact otherwise the joint can be forced apart by the foaming action. The strength is good and it will be more than adequate to hold your bush in place
|Bill Chugg||07/12/2018 09:56:00|
|149 forum posts|
Chap had a problem at the boatyard with these . Sorted it for him by making a bush from ordinary , for lack of a better word, bronze,
He had bought oilite ones.
|Chris Trice||07/12/2018 11:31:11|
1034 forum posts
Please login to post a reply.
Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!
You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.
Click THIS LINK for full contact details.
For subscription issues please see THIS LINK.