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Landlubber
27th Feb 2010, 05:07 PM
My home made boat trailer is now ready for galvanising, I phoned the local fellas here and was told 5-600 dolars for the job. It is only for a 4 metre dinghy, so this is more than the parts cost me.

Does anyone have any recomendations on this issue please.

ian
27th Feb 2010, 10:56 PM
there's more than meets the eye to galvanising.
with luck Eddie-the-Eagle will see and chip in, but from memory galvanising requires that the item be throughly cleaned, then dipped in a pickling bath to prepare the metal so the zinc will adhere to it, then you get to the hot zinc bath, and then I think there's a one or two steps after the hot bath.
It's a lot of work and the cost will be relatively insensitive to the size of the item galvanised.

Charleville
28th Feb 2010, 09:15 AM
An interesting topic to me also simply because my eight year old boat trailer is showing a bit of rust. Surface rust, I hope!

What preparation is required on such a trailer to get it ready to be re-galvanised, please?

I assume that the rust should be removed with an wire brush on a drill or angle grinder but does anything else need to be done by the owner?


.

danielhobby
28th Feb 2010, 11:56 AM
hi all,the galv process of stripping surface paint old galvinizing etc is usally taken care of when they pickle the job,if its heavy paint or some paint types(black etch primer comes to mind)then its a good idea to sandblast the job.the main reason boat trailers and roof racks etc cost as much as they do is they take up a lot of the "frame"(hanging space per rack) and are charged as such.i have the same problem when i get a spiral stair galvanised fully assembled,it costs about $800/900 versus $350 for the same stair in pieces.normal costs for galvanising is about $1-00 per kilo job weight.regards danny

Charleville
28th Feb 2010, 02:34 PM
hi all,the galv process of stripping surface paint old galvinizing etc is usally taken care of when they pickle the job,

..........regards danny


Many thanks for that info, Danny.


:2tsup:


.

malb
1st Mar 2010, 07:09 PM
Galvanising is often charged by weight of Zinc used, plus service charges. Goods weighed when left and again when finished, Increase in weight represents the zinc adhering internally/externally.

Hollow sections should be drilled with adequate diameter holes at appropriate points to evacuate air as the unit is lowered into baths and drain solutions/molten zinc as it is withdrawn. Because of the danger of explosive splitting of tube due to air expansion if sealed, the galvanisers will either refuse the job or drill holes to their requirements if you do not provide appropriate holes. It is strongly reccommended to consult the plant foreman/supervisor before leaving the job.

Franklin
2nd Mar 2010, 11:35 AM
I have been quoted prices from $1.30 to $2.00/kg (weight after galvanising) by the galvanisers over here in Perth. I have also been told that galvanising will add about 8% to the mass. I expect it will cost me close to $1000 to dip my trailer.

Also advised that old paint and already galvanised metal will cost heaps extra as this must be stripped off prior. Also told to avoid mesh as this cost a lot as they have to file off all the dags everywhere.

A mate works at a fabrication place attached to one of the galvanisers over here and he said that when they got busy last year they sent some of their work to the competition. Apparently when it came back they were all standing around admiring it, he said the quality of finish was a lot better than what they achieved. Not sure how this is possible, surely hot zinc is hot zinc!

malb
2nd Mar 2010, 06:10 PM
Finish quality is a function of bath cleanliness, let dirt, dust, grease, metal dags etc into the bath and it stays for a long time.
There is no practical way to replace the molten zinc in its entirety without reworking the bath. This involves withdrawing the bulk of the zinc, or consuming it with jobs and not replacing it, shutting down the bath and allowing it to cool, cutting up, chipping out and removing residual metal, cleaning the bath, reloading and reheating. Overall a slow and expensive operation, prone to damaging the heating systems etc due to thermal shock and impact.
Some baths I have come accross have run continuously for many years and have a significant amount of crud in the bottom.

Landlubber
4th Mar 2010, 04:06 PM
When I phoned the local galvanisers they informed me regarding the holes in every end of every section to avoid blowback, what I am interested in is if anyone can recommend a Brisbane galvaniser that they know does good, reasonably priced work.

My quote at 600 is way too dear in my reckoning, that would be 300 kilos of zinc @$2/kilo....no way on such a small job

Ta, John

SurfinNev
4th Mar 2010, 07:43 PM
What's the length and width of this trailer?

Nev

Bazzmate
4th Mar 2010, 08:24 PM
My quote at 600 is way too dear in my reckoning, that would be 300 kilos of zinc @$2/kilo....no way on such a small jobTa, John

If it helps . . . I have an Oct 2008 price list from a local trailer manufacturer up here on the Sunny Coast and as an optional extra, he offers hot dip galvanising of a 6x4 trailer for an extra $655.00. (7x4 an extra $700 and 8x4 an extra $755) In those prices, I guess you would need to take into account transport to/from Brisbane, his margin and that the prices are about 1.5yrs old.
_______

Pricing might also have something to do with the galvanisers fixed operating costs and whether they can recoup their costs (plus profit of course) by packing the bath with a number of items at once (in effect, sharing the costs) or only being able to dip one odd shaped item at a time such as a trailer?? . . . that's just a guess:?.
Cheers

ian
4th Mar 2010, 09:23 PM
John
danielhobby, above gave you an indication of how pricing for galvanisatio is structured
1) you are charged an amount per kg for the Zinc used
2) in addition to the zinc, you are also billed for the space the item occupies in the factory.

daniel's example was a set of spiral sairs
in pieces the cost is ~$350
assembled the cost is $800–900
that works about at about $500 for the extra space the asembled stair requires

On that basis, your quote might represent $50 worth of zinc and $550 of factory space

Landlubber
5th Mar 2010, 08:07 AM
OK fellas, I see that my quote seems about par for the course, so I will just go agead and get it done.

Thank you all kindly for your comments and advice. It is a nice trailer and worth looking after.

Thanks again all, John

eddie the eagle
14th Jun 2010, 08:44 PM
there's more than meets the eye to galvanising.
with luck Eddie-the-Eagle will see and chip in, but from memory galvanising requires that the item be throughly cleaned, then dipped in a pickling bath to prepare the metal so the zinc will adhere to it, then you get to the hot zinc bath, and then I think there's a one or two steps after the hot bath.
It's a lot of work and the cost will be relatively insensitive to the size of the item galvanised.

Hi All,

Ian's correct - the galvanising process is summarised well enough by all here. I learnt something too, commonsense = trapped air expanding, but I've never worked in galvanising, acid pickling at the rate of 1500tpd, yes, galvanising, no.

Cheers,

eddie