Wishbone coating ?
Discussion
Having just read the thread on the chest wig forum HERE relating to difficulties fitting new bushes.
My wishbones will be going for blasting and powder coating in the near future and I’m not sure what to do about the internal diameter where the bushes fit into.
Should I get the whole lot coated then remove the powder coat from the bores to fit the bushes ?
If so, how do you remove the powder coat from the internal bore without damaging it else where ?
Or should I tape off the internal bores (cant see that being easy) before they go for coating ?
My wishbones will be going for blasting and powder coating in the near future and I’m not sure what to do about the internal diameter where the bushes fit into.
Should I get the whole lot coated then remove the powder coat from the bores to fit the bushes ?
If so, how do you remove the powder coat from the internal bore without damaging it else where ?
Or should I tape off the internal bores (cant see that being easy) before they go for coating ?
The problem was caused by some wishbones being very tight with the internal ID and in some cases, the tolerences all work against you. I had a long discussion with Powerflex about this problem mentioned on the Griff forum and they are going to slightly change the length so that in tight wishbone cases, there is a little bit more scope. What happens is that with tight IDs, the bushes get squashed and lengthen. This means that they are slightly too long to fit and instead of getting a nice free movement it is very stiff because the longer bush fouls on the thrust washers.
The key point is that the wishbones should not be powder coated internally as this will make the ID too small and the bush will be squashed beyond its design.
While it may be tempting to get the wishbones blasted and coated and then remove the bushes, the bush removal is more than likely to damage the powder coated especially if you get a sticky one or have to cut one out. It is a violent process even when they come out easily.
The poly bushes should push in without the need for any excessive force. If this is needed then there is an ID problem.
I have checked the bushes I have in stock and they are at the smaller end of any tolerences. I have agreed with Powerflex that, if any of my customers find they have a wishbone with a tight ID, then I can modify the bushes accordingly. Alternatively, if you measure the IDs before coating etc and let me know, I can advise you whether there might be a problem and organise a special set if needed.
As I have said, this is very much an exception as the vast majority of bushes simply push in.
If you have any further questions please contact me.
The key point is that the wishbones should not be powder coated internally as this will make the ID too small and the bush will be squashed beyond its design.
While it may be tempting to get the wishbones blasted and coated and then remove the bushes, the bush removal is more than likely to damage the powder coated especially if you get a sticky one or have to cut one out. It is a violent process even when they come out easily.
The poly bushes should push in without the need for any excessive force. If this is needed then there is an ID problem.
I have checked the bushes I have in stock and they are at the smaller end of any tolerences. I have agreed with Powerflex that, if any of my customers find they have a wishbone with a tight ID, then I can modify the bushes accordingly. Alternatively, if you measure the IDs before coating etc and let me know, I can advise you whether there might be a problem and organise a special set if needed.
As I have said, this is very much an exception as the vast majority of bushes simply push in.
If you have any further questions please contact me.
shpub said:
As for removing the powder coating... best way is to not get it there in the first place. Talk to your coaters as they must have some preferred ways of doing this.
Easy way is to use some surplus nuts and bolts, and washers whose diameter is slightly bigger than the internal bores on the wishbones etc. Clean and prep all the internal bores, then protect with nuts and washers, [see pics] when powder coated, remove all the nuts, bolts, washers etc refit new bushes.
Last pic shows new poly bush in place.
Edited by TJC46 on Thursday 6th January 16:59
Surfaces of wishbones must be shot blasted to clean material and provide a good roughened surface for paint adhesion. If not shot blasted the coating wont last long as the wishbones flex under load loosening any paint from the surface. Paint can be pretty inflexible, especially Hammerite. IMO parts are best shot blasted, then painted with a sacrificial primer followed by a coat of good flexible paint as used by OEMs to protect lower body areas (available from Halfords). If needed this can then be painted a colour of choice. Wire brushing and painting directly on to surface will have limited life.
Steve, Thanks for that. I have a set of your bushes and bolts sitting in a box ready to fit. I'll give you a call if there's a problem.
TJC46, Good idea i think i might use that method, after giving the bores a bit of a clean with some sandpaper.
Old bushes are out already just need to dismantle the hubs before it all goes for blasting / coating.
TJC46, Good idea i think i might use that method, after giving the bores a bit of a clean with some sandpaper.
Old bushes are out already just need to dismantle the hubs before it all goes for blasting / coating.
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