Farmweld Posted February 27, 2012 Share Posted February 27, 2012 I was just wondering if it would be worth starting a new forum topic along the line of "Finishes" for both small and large items. The reason I asked was because I have just been asked to quote on a pretty big job involving a spiral staircase, 2 x curved staircases, about 50m of balustrade and handrails, about 30m of front fence, a couple of balconies, and lots of gates 2.4m tall or taller and varying in length from 1.2 to 6m. Some are internal and will have to be carried into the building for installation in pieces, others external and will need protection from the weather. I was wondering what others on this forum would use in these situations and a search only throws up mainly knife smithing or small item finishes. I need some advice on big stuff. The outside stuff we are looking at either hot dip galv. (which will bugger up any fine detail work) or zinc plating, any advice on either? The inside stuff which will have to be carried in will need some finishing and/or touching up once it is installed, any advice on which types of paint/powdercoat/crayon/mud to use would be greatly appreciated. I don't like having to sit down and quote out these big jobs because there are so many variables involved and the finish that I need to steer the customer towards to make my life easier is just one of them. Andrew Quote Link to comment Share on other sites More sharing options...
dablacksmith Posted February 27, 2012 Share Posted February 27, 2012 ide go powder coat.... but its kinda hard to reccomend finishes because the weather and availability of finishes makes a difference..big items end up more toward the industrial .... not where most of the people on this forum are at.I aplaud your willingness to tackle the big jobs and especially spiral staircases!ive had exactly one experience with spiral staircases and will never mess with another...good luck! Quote Link to comment Share on other sites More sharing options...
John B Posted February 27, 2012 Share Posted February 27, 2012 I was just wondering if it would be worth starting a new forum topic along the line of "Finishes" for both small and large items. The reason I asked was because I have just been asked to quote on a pretty big job involving a spiral staircase, 2 x curved staircases, about 50m of balustrade and handrails, about 30m of front fence, a couple of balconies, and lots of gates 2.4m tall or taller and varying in length from 1.2 to 6m. Some are internal and will have to be carried into the building for installation in pieces, others external and will need protection from the weather. I was wondering what others on this forum would use in these situations and a search only throws up mainly knife smithing or small item finishes. I need some advice on big stuff. The outside stuff we are looking at either hot dip galv. (which will bugger up any fine detail work) or zinc plating, any advice on either? The inside stuff which will have to be carried in will need some finishing and/or touching up once it is installed, any advice on which types of paint/powdercoat/crayon/mud to use would be greatly appreciated. I don't like having to sit down and quote out these big jobs because there are so many variables involved and the finish that I need to steer the customer towards to make my life easier is just one of them. Andrew A lot will depend on what is available to you locally. Personally I prefer hot zinc spraying to dipping or plating, you can paint directly onto the finish, the finish will show detailed forging work and is akin to a light sandblast giving a good key to apply paint to, you can also get bronze, brass, copper, and aluminium finishes that are a finish in their own right, the aluminium gives a pewter like finish. Indoor work I would clean, prime, undercoat and topcoat (as many as you want to put on), any chips can be touched in after installation. I would not consider powder coating, as I find it susceptible to lifitng due to temperature differentials and if it chips at installation, it should all have to be redone again. If the client required a really durable finish, stove enamelled would be the way I would go. Big projects are really a pain to do, not only the estimating, ensure stage payments and be prepared to turn other work away during the course of the project, jobs like these can make or bankrupt you Good luck with it, Quote Link to comment Share on other sites More sharing options...
OzMatt Posted February 29, 2012 Share Posted February 29, 2012 Hey Andrew, Is this for a private job, or through a builder/architect? Have they given you any idea on preferences for finishes? I would say that for thee internal stuff, if you could bolt pieces together, then a powder coat finish would be ideal, but if you have to weld pieces after fitting it rules out that option. As far as outside finishes, I would be interested to hear which way you end up going, as I am trying to decide for my own project. Cheers, Matt Quote Link to comment Share on other sites More sharing options...
Astro_Al Posted February 29, 2012 Share Posted February 29, 2012 In my experience galvanising is much more durable than hot zinc spraying. If the work is quite 'bold' with not much small detail then hot dip galv it, if not, get it hot zinc sprayed, which should include a preparatory shot blasting. You need to treat galved stuff with mordant or 't-wash' before painting, whereas hot zinc spray can be directly painted or primed after treatment. After that, the finish depends on what the client wants. I would always avoid powder coating large items due to the likilhood of it being irreparably damaged during installation. Good luck, Al Quote Link to comment Share on other sites More sharing options...
Farmweld Posted March 1, 2012 Author Share Posted March 1, 2012 OzMatt, this one is through a builder and its a bit of a pain because they haven't come up with a design/drawings of what they want, but they want an "estimate" of what it could cost and how long it will take! It's become a take a rough look at the list of things they want, pluck a number out of the air, add my mobile phone number, times it by the date, deduct grandmothers birthday, and add the dogs age as a percentage of the total exercise. Double pain because of the size/cost of the job, it will have to be made up in sections and either welded together onsite (which I don't want to do as the whole lot is being epoxied into the marble) or I have to make concealed latching that will lock up once it is epoxied in. Astro_Al, thanks for the heads up about the metal spraying. I haven't had a chance to chase it up but I've heard there is someone local who does it, just need to find out the cost. John B, thanks for your words. Yes it is one of those make or break jobs and it is rapidly turning into a headache. We would love to have a go because of the size and potential profit, but it is going to tie the workshop up for at least six months and possibly a lot more, and we may have to employ another person to keep the regular work going during that time. We just have to sit down and do the sums and decide whether we want to go for it or not, and then the customer has to decide if he wants to pay that much, and then we have to hammer out a contract re supply and payments. Just to top it all off we had another builder ring us yeaterday with a similar, but considerably smaller, job yeaterday. Andrew Quote Link to comment Share on other sites More sharing options...
John B Posted March 1, 2012 Share Posted March 1, 2012 In my experience galvanising is much more durable than hot zinc spraying. If the work is quite 'bold' with not much small detail then hot dip galv it, if not, get it hot zinc sprayed, which should include a preparatory shot blasting. You need to treat galved stuff with mordant or 't-wash' before painting, whereas hot zinc spray can be directly painted or primed after treatment. After that, the finish depends on what the client wants. I would always avoid powder coating large items due to the likilhood of it being irreparably damaged during installation. Good luck, Al Durability, both Hot dip and zinc spray can be guaranteed by the applicators for the same period of time Having said that hot dip IME gives more problems her in the UK. Hot dip can and usually does need fettling, sharp pieces, inclusions and lumps are present after the process. The item being hot dipped, particularly the larger items are more prone to damage and distortion due to handling and the excuse I have been given more than once is "Heat distortion whilst in the process", more like careless or ill trained operatives, and getting compensation or damages is very difficult, read the small print. This is not just my experience, I know others who can tell of similar ones, one in particular of a spiral staircase handrail that was meticulously made and when it came back from the galvanisers was distorted beyond simple repair and had many pieces with zinc icicles attached that had to be removed carefully lest base metal be exposed. Those are the main reasons I prefer the Hot Zinc spraying, the operatives also seem to take more pride in the finished product, it may be different elsewhere but this seems general for south west UK Quote Link to comment Share on other sites More sharing options...
Larry H Posted March 1, 2012 Share Posted March 1, 2012 Don't fear, drag your feet on the big job and take the smaller job as your learning curve. I know its out dated but, consider the old fashion way of finishing, zinc chromate for a primer and your topcoat......applied by brush, It worked in the "old days" and is very durable and long lasting. I hired a painter who knew how to paint....big difference, good job Quote Link to comment Share on other sites More sharing options...
canada goose Posted March 1, 2012 Share Posted March 1, 2012 I have only heard of using zinc chromate as a primer on aluminum. Is it really used on steel? Quote Link to comment Share on other sites More sharing options...
Drewed Posted March 1, 2012 Share Posted March 1, 2012 I really love the the people who want "just a rough guess" at a price then a year later, with a whole differnet set of specs, want to hold you to your "quote." Quote Link to comment Share on other sites More sharing options...
John B Posted March 1, 2012 Share Posted March 1, 2012 I have only heard of using zinc chromate as a primer on aluminum. Is it really used on steel? Yes , but a different colour, Yellow for aluminium, red (sort of) for ferrous. Quote Link to comment Share on other sites More sharing options...
Colin Davies Posted March 3, 2012 Share Posted March 3, 2012 I have no personal experience, but I'll pass on what I've been told as it hasn't been mentioned yet: There's a process called E-coating that can be used as an alternative to hot-dip galvanizing. It's conceptually similar to electroplating, and what you get is a base coat that penetrates every crevice of the treated piece and is perfectly adhered. I'm told it provides an excellent substrate for surface coats, is better for preserving detail, and resists cracking. You also don't have to worry so much about allowing for flow and drainage during the process. As I say, I have no personal experience with the stuff, but it was presented to me as being as-good-or-better than hot dip by someone who knows his stuff, so it may be worth looking into. Colin Quote Link to comment Share on other sites More sharing options...
Astro_Al Posted March 3, 2012 Share Posted March 3, 2012 Durability, both Hot dip and zinc spray can be guaranteed by the applicators for the same period of time Having said that hot dip IME gives more problems her in the UK. Hot dip can and usually does need fettling, sharp pieces, inclusions and lumps are present after the process. The item being hot dipped, particularly the larger items are more prone to damage and distortion due to handling and the excuse I have been given more than once is "Heat distortion whilst in the process", more like careless or ill trained operatives, and getting compensation or damages is very difficult, read the small print. This is not just my experience, I know others who can tell of similar ones, one in particular of a spiral staircase handrail that was meticulously made and when it came back from the galvanisers was distorted beyond simple repair and had many pieces with zinc icicles attached that had to be removed carefully lest base metal be exposed. Those are the main reasons I prefer the Hot Zinc spraying, the operatives also seem to take more pride in the finished product, it may be different elsewhere but this seems general for south west UK Yes, that's true John, I have had some stuff distort badly when being galvanised. It's the internal stresses of the cooled welds that do it. I had to drive my forklift over some parts to straighten them out, worked pretty well though! I don't think it's a 'take more care' thing, the fact is that hot spraying doesn't get the metal as hot as hot dipping. There isn't much a hot dipping operative can do, he just lowers it in and pulls it out... Regarding durability, they might be similar when finally painted etc (I.e. offer the same protection from the elements and weather), but the hot spray will be much more easily damaged by the forklift etc just getting back to the workshop and in transit, it's not half as tough as dipped. I'd be happy to dip something as its final coating, but not happy hot spraying as the final coating. Cheers, Al Quote Link to comment Share on other sites More sharing options...
John B Posted March 3, 2012 Share Posted March 3, 2012 I can take a bit of distortion, but the items that were damaged at the hot dippers was due to careless handling/slinging, one had a H section beam dropped on it, another rolled off the lorry it was being loaded onto causing severe distortion and denting, and so the list went on, not just one place either, That is one of the main reasons I went to the spraying, (and a minimum £50 handling charge +collection +return) If the client wanted hot dip, I finish mey bit and let them take care of that, That way it saved them my handling costs etc and relieved me of any hassle with the dippers. Hot spraying is not an "as is" finish in my book, having said that, we have a hot sprayed gate that is in an exposed weathering area, subject to wind chill and sun exposure, has a fair amount of traffic and knocks, and was installed 10plus years ago, no evidence anywhere of discolouration due to rusting, a little bit of shine where metallic contact has been made, this appears to be burnishing the finish as opposed to going to base metal. Overal appearance is a matt battleship grey, maybe get round to painting it one day, Quote Link to comment Share on other sites More sharing options...
Farmweld Posted March 7, 2012 Author Share Posted March 7, 2012 Thanks for all of the replies. There are two main hot-dip places locally and I am going to have to do some research as to their "performance". I've heard there was also a metal spraying place set up for a lot of the stuff that goes up to the mines so even more research. Still waiting to hear back from the customer but it's always good to learn something new from others. Thankyou very much. Andrew Quote Link to comment Share on other sites More sharing options...
iron woodrow Posted March 7, 2012 Share Posted March 7, 2012 be prepared for the eventuality of the welds "swelling" after hot dip galvanizing. this can be rather unsightly. it really shows up on the "hide the weld" style of work, where a perfectly hidden ground weld will show up in all its glory.... i had one bloke try to tell me that 'the welds swell and if you grind it back you will hit the swolen weld metal. dont let anyone tell you this, because it is the zinc being drawn to the join and the difference in metal and developing a thicker layer, which can be sanded flush again, but it is a lot of work..... i have had some bad experiences with powder coating, and i do not like it, both as a finish, and as a product..... Quote Link to comment Share on other sites More sharing options...
ianinsa Posted March 7, 2012 Share Posted March 7, 2012 There is a vast chasm to fall into when powdercoating hot dip galv. We have heaps of experience on work for 5* hotels in Dubai=hot,humid & right at the beachfront. Firstly deliver and fetch the goods yourself - 90% of the damage is during transport. Secondly as a smith you should know about differential expantion and contraction of different metal sections so a thick flat bar welded to a thinwall tube is asking for problems if you intend to hot dip, often the same problem in powdercoating ovens. Many powdercoaters tell you that its not nessisary but you have to resand the whole job to remove drips and to flat welds.then bead or soda blast the whole job- now powder coat with base colour- Interpon-D powder is g/teed to be uv stable - you can then paint technique with acrylic paints or use Baroque art gilders paste- then powdercoat clear over it.Done properly powdercoating is fantastic done badly well.....This is an industry where my mate recons "how do you know if your powdercoater is B/Sing you?.. his lips move!" its not easy to find a good one, but if you do you will treasure him/her. Yes, you can clear powdercoat over Baroque art gilders paste, Also the powder for clear is available that ends up softer and more tactile. I know it takes time but it certainly has been worth my time to visit both powdercoaters and galvanisers to not only understand the process but get them to advise on common pitfalls. We have had bad experiences with electroplated zinc as it does not plate the inside so you get rust leaching out. I'm afraid I have no experience with metal spray so I can't give objective comparisons. Sorry if I sound like I'm lecturing. Ian Quote Link to comment Share on other sites More sharing options...
Farmweld Posted March 8, 2012 Author Share Posted March 8, 2012 Thanks again for the replies. I've had a fair bit of experience with getting the pipe and RHS gates we make powdercoated. Found a good one eventually who will sandblast, then prime, then colour coat. Plenty around who will just slop the colour straight onto the gal pipe and pray that it sticks (it doesn't). We've only had two jobs hot dipped by one place so not as much experience there (not the greatest job either, drips, buildup, and a couple of dings) and I want to try some of the other places which have been recommended by my poowdercoater. He uses the Interpon powders as well. I've also had trouble with some cast jointed gates that we make cracking joints in the oven, could have been a bad batch of castings as it's only happened three times now (could have been some dodgy welding as well). All I know is it stinks and makes a hell of a mess fixing them up so they can go back for re-coating. Thanks also for the tip about the gilders paste, might have to try that on some highlights next time I get a fancy job. Andrew Quote Link to comment Share on other sites More sharing options...
ianinsa Posted March 8, 2012 Share Posted March 8, 2012 Andrew, A lot of guys use Bondo or similar to fill imperfections and it just deos not work well with the powder coat, I have found that some types of epoxy putty do the job well.(after galv. that is) Ian Quote Link to comment Share on other sites More sharing options...
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