galvanising threads how to protect them

[@Turbo]

I have a walkway that is going for galvanising however there is one thread in it to join the walkway to the handrail.

what can i use to protect the thread from the galvanising?

i have seen a sort of putty used before that was applied to the threads but forgot to ask the fella what it was called...

anyone help me out?

 

[Pete.]

I wouldn't mess about - I'd re-cut the thread afterwards.

 

[@Turbo]

I could pilot the hole then tap it afterwards that would be a good option.

got a rate of 50p per kg. its a small job so probs not the best rate how does it compare to prices others are getting?

 

[Hitch]

100%, just pilot it, then galv.
Drill out and retap when you get it back or when you install it.

 

[Welderpaul]

Not a bad rate. We pay 22p a KG for decent sized jobs (3-4t), up to 30p a KG for odds and sods.

Tried the masking paste, very costly and doesn't work very well. It has a tendency to melt and run onto the rest of the job and spoil the finish. As others; just tap afterwards.

 

[Beanmetalworks]

were are people getting there galv done ?? is that what your on about when you say 22p kg? just curious as im paying more than that?

 

[Welderpaul]

We spend maybe 4-5 grand every month with them for hot dip galv and for powdercoating so can command some good rates.
I think their rate for 'the man of the street' is 500 quid a tonne.

 

[Wedg1e]

Can't you just screw a longish bolt in (leaving the head clear of the surface), have the galv done then unscrew afterwards?

 

[gav0994]

Can't you just screw a longish bolt in (leaving the head clear of the surface), have the galv done then unscrew afterwards?

done that before and it was a total nightmare trying to get the bolt out afterwards! The galv finds its way into the threads and galvs the bolt into place! ended up snapping the bolt and having to drill out and re-tap the hole.

I now just put normal general purpose grease into any threads before galvanising and have had no problems at all. Last job I got done I only had to run a tap through one hole, the others were perfect.

 

[Welderpaul]

I've snapped M16 bolts when we once tried to protect threads with them and battled to get them all back out again. We greased them too.

 

[bs2236]

We were advised to full some m20 blind holes in some bosses with bathroom sealant before sending for dipping. Total disaster, in some cases the bosses were full of galv, was a nightmare to sort out and cost thousands to sort out in the end.

for the rest of the production run we pilot drilled them and machined the threads post galv.