Steel base instead of aluminium?

Actually, I think steel would be good contingent upon the type. Depends how easily your base will rust. The good thing about the aluminum bases on the market is that they are generally pretty much anodized on the top surface.
This helps to prevent oxidation.

A steel base is liable to need a coat of oil on a regular basis; the main problem with this being that generally, oily surfaces don’t do to well with adhesives. So, when you consider that coating 5 sides of your base with oil and regularly scrubbing the other will do the trick, you can probably safely assume that a steel base is a reasonable alternative.

(what I mean is, a light coat of oil on the bottom of the base, a light coat of oil on the other 4 sides, and a clean top surface.)

Just make sure that if you’re going to leave it sit for a couple weeks you put a nice coat of oil on it and clean it off again before you try to stick a plate to it.

Thanks HavenPress, I had the same thoughts regarding the oxidisation, so i’ll keep that in mind.

Still, oiling the base after use, then cleaning with kerosine prior to use might still work. Especially if the price is right.

They’ll also laser etch a grid into the top surface too!

I had an aluminum base machined for me locally. The machinist also suggested steel at some point. I just figured it would be too heavy for a 9x12 base.
There are coatings to prevent steel rusting, you should probably look into that. My base has no grid and has served me well. Here’s a photo. So yeah, actually I went with something smaller, because of my budget at the time.

base.jpg

I remember steel cutting dies that were10x15 and they were almost unmanageable in their weight , however 5x7 would be ok for small machines . Mind your feet ….

Steel should work well, and will not rust if kept away from humidity. I have lots of steel furniture, and don’t have issues with rust even in our humid Iowa summers.

The weight is an issue if going very large, but then it will provide exercise for the press operator as well. Lasing a grid may be good, but don’t let them make the pattern very deep, and make certain it doesn’t raise a bit around the marking. Probably not too much of an issue as you will be using a double-coated film adhesive layer and a thicker polymer plate. It most likely wouldn’t “telegraph through” to the image layer.

If I’m not mistaken, the marking of the Boxcar bases is done with a dye image at the time of anodizing (at least it looks that way to me) so that there is no disruption of the surface (no depression in the marking area).

John Henry

Has anyone simply bought 7/8” mic6 AL plate and used it with standard relief PP plates? It looks to cost about $100 for a square foot, and should be more than precise enough. Based on Boxcar’s description of the material, I’d guess they simply buy this and get the grid and anodizing done. They probably have to get the deep relief plates blanchard ground, but the standard 0.875 comes off the shelf.

http://www.mcmaster.com/

86825K85

I’d be surprised if you can get steel that accurate for that price, but it should work just fine if you did. Keep it clean and dry and it shouldn’t rust. If it does, use a flat sharpening stone (like a Norton fine grit) and some thin oil like wd-40 to carefully ‘stone’ the rust off off the surface, while keeping it flat.

303 high-grade stainless steel is highly resistant to corrosion and non magnetic. It can be ground to deadly accuracy. Bunting Magnetic makes steel bases using similar.

http://bielerpressxi.blogspot.com/2008/05/bunting-magnetic-cerface-flat-...

I had some roller gauges made up with this steel a while back.

http://www.flickr.com/photos/bielerpress/313123010/in/photostream

Gerald
http://BielerPress.blogspot.com

Give or take, how much does a bunting base about 16x22 image capability cost, Gerald?

And same for 12x18/13x19 apprx. image capability?

Well, as the saying goes, if you have to ask, you can’t afford it.

Bunting’s largest standard size is 8-1/2 by 11-1/4 inches. They do not make larger than this because they feel they cannot guarantee its precision beyond that. They make bases to fit the chase size of all the major commercial grade presses but recommend combining bases to achieve this. They will make larger custom sizes, up to 19 x 39 but suggest they be bolted to the press bed. They are a major manufacturer of magnetic products across all industries and have been making magnetic flatbases since 1985 so I’ll go along with them on all this. These bases are not just flat aluminum stock.

But you asked about price. I have two MB811 Buntings in my SP15 and four in my Universal III. Today’s cost for the SP15 bases would be exactly $1,956 and twice that for those in the Uni. I say today because Bunting raises it’s price 5% like clockwork every year on January 1. The bases rarely surface on the used market and because of the purposeful (or not) inflation (and the fact that they never wear out) used bases tend to sell for not less than what you bought them for. If I had the dough-re-me I’d invest in these before gold and silver. Though, in terms of investment, if anyone would have thought about it long enough a decade or so ago, they would have bought up every Vandercook out there. :—)

Is it worth it? For me it sure is. There are never any problems with the bases or the plates, nothing to worry about in that regard. Basically, the bases serve as a raised bed, out of sight, out of mind. A permanent fixture that results in one less factor of concern in the presswork equation.

Gerald

This whole topic of base materials comes up regularly…. and I must agree that if if you and your press demand a highly precise base (like a Vandercook does) then nothing beats a Bunting Base. I’ve got two of them, and use them regularly.

But…. if your press or process doesn’t need such precision (like printing posters on soft stock with a sign press) then you can get by with far less expensive alternatives. As mentioned above, it all depends on what you are printing, and what you are printing with.

For old letterpresses like a C&P that probably has worn bearings and a bit of play, using a flat-ground mild steel plate from McMaster Carr makes a lot of sense. They are cheaper, and certainly within the tolerence range of your machine. For smaller machines, like a Kelsey, you can even get by with high quality wooden bases, IF you are willing to go to the extra effort of careful makeready.

None of this is rocket surgery. Before you spend a lot of money on an expensive base, I’d recommend trying out some of the less expensive alternatives first. Then when they work just fine, you will have saved a lot of money.

Can not quite comprehend (at this stage of the game) all the in-depth post re mounting base, 50 years ago when letterpress was king and 4 colour via L/P was the norm, BIG, Meihle,s with the Cylinders coming in at 3 imperial tons, ran day and night around the clock, printing 4 colour with 32 pages up, with absolutely no waste of time, rabbiting about the merits of this base, that base, and where when how etc, etc ad in-finitum. Plates were mounted on infinately variable, perfectly recyclable, mounting base, re jigged for next job,at the flick of the job docket!!!! Usually one of three systems, first 3 em X 3em high quads, from the Super caster to accomodate 64 thou plates plus D.S.A. second 6 em X 6 em high quads with 4 wooden inserts to accomodate plates with flanges for tacking down or D.S.A. and thirdly manufactured 6 em X 6 em aluminium high quads (or quotes Peter will cross the “t” s and dot the “i”,s) which also had wooden inserts for 64 thou plates. The ELROD Also produced and still IS producing a perfectly good system, in girder form to perform the same job. And with the use of a pre make-ready galley, lay down the mounting base in any configuration, i.e full out, half or quarter page inc type, or around any configuration, blocks included. Can your fancy ready made box c**p even think of that!!!! 60 years ago it would be made up,IN REGISTER (with pre make-ready galley, every comp had his own, which included sheet of film, hatched and graphed, with pinbar, automatically filed in the job docket!! with one pull on the film) and on the run, whilst you are still attacking your 21st century qwerty keyboard>>> Is this progress???? Plus re the “to engineer or not to engineer” once again NOT rocket science, ANY reasonable Engineer with a milling machine, who can fly cut a big Yankee Muscle Car, ALUMINIUM CYLINDER HEAD to very, very, precise limits, would almost certainly, find it a doddle to manufacture a tiny printing press mounting block, to whatever height you need, * see footnote (unless of course we have to be seen using “X” brand or “Y” brand), at WHAT COST???? >>>>>>> * plus it would be reasonable to Assume/Expect that Your Engineer, would consult his stockholder supplies Catalogue, and ascertain precisely which grade of aluminium, would perform best for your requirements!!!! not which type, can be acquired in bulk/cheapest for most profit.***

Oh, Gerald, I wasn’t asking because I was questioning the worth- I think they’re certainly worth it, and I ask because
A. I have never noted the price of one that came up used (as you addressed)
B. I am considering the purchase of a set for my Uni-II.

Right now I have a very-very flat steel base that came with the press, and it had been ground down so that one could mount magnetic rubber to it; but the rubber that came with it was warped and bubbled up and pocked.

Recently I removed the rubber and stripped the top surface of the base. I have been intending to adhere some new rubber to the surface of this steel base with 2-tack sheet, though I think it’s possible the rubber I use will be too thin for the purpose. Although I have an adjustable bed, so that works in my favor. I can lower/raise the base as needed to compensate for the final plate thickness in relation to type height, but what I’m looking for at this point is the right kind of rubber to use that will resist compression. I managed to get some inexpensive (2.00 a foot) sheet material from Mcmaster as a test, and I guess I’ll see where this gets me, but I’m looking for something that is really really rigid.

Failing this (almost free) approach, I suppose it’s possible that a set of bunting bases is in order :-)

Anyone have any suggestions for magnetic sheet material, or is this a tree I shouldn’t bark up/care to share your actual experiences?

I’m aware of plate shift and creeping that can happen over time with inflexible materials when printing on a flatbed cylinder press, and I’m just sort of wondering how big of an issue a thin/nonrigid flexible magnetic material will be.

Oh, I should mention that the press came from a shop which was producing steel dies, and the base is certainly very low (it was .774” with rubber when I got it) allowing for a very thick die to be proofed.
I’m pretty certain I can raise the base higher using the A/B and use a thinner sheet of magnetic rubber; I plan to use as thin as possible to avoid distortion.
I’ve posted plenty of comments about bases in the past for plastic backed polymer, and I have extensive experience with that stuff, but I have no experience with magnetic bases :-)

Up till now, it’s been good old spray adhesive or 2-tack to mount plates.

HavenPress

The well-known PatMag uses a magnetic rubber sheet called MagBack (sp?). It is used for holding steel-backed plates to the platen of a platemaking machine during washout. This was available from A&V (and still might be) but their newer machines don’t use it. I started with PatMags and that is what hooked me on the process. But the magnetism is quite weak and the plates do travel. Then I purchased a Bunting and it was a world of difference. Never looked back.

But if you are intent on going in this direction contact Bunting. Their big catalog lists all kinds of flat magnetic sheeting for all kinds of applications, thick/thin/ different strengths, etc.

Don’t throw away that steel base. Their density comes in handy for mounting linocuts and all sorts of other materials that you might need to get to type high (without the problem of a weak base (wood, etc) distorting the image.

Your A/B should serve you well in making whatever adjustments are required.

One very good quality about the magnetic sheeting is that it provides a nice kickback. This can save a plate that is undergoing cruel and unusual punishment.

Gerald

HavenPress

The well-known PatMag uses a magnetic rubber sheet called MagBack (sp?). It is used for holding steel-backed plates to the platen of a platemaking machine during washout. This was available from A&V (and still might be) but their newer machines don’t use it. I started with PatMags and that is what hooked me on the process. But the magnetism is quite weak and the plates do travel. Then I purchased a Bunting and it was a world of difference. Never looked back.

But if you are intent on going in this direction contact Bunting. Their big catalog lists all kinds of flat magnetic sheeting for all kinds of applications, thick/thin/ different strengths, etc.

Don’t throw away that steel base. Their density comes in handy for mounting linocuts and all sorts of other materials that you might need to get to type high (without the problem of a weak base (wood, etc) distorting the image.

Your A/B should serve you well in making whatever adjustments are required.

One very good quality about the magnetic sheeting is that it provides a nice kickback. This can save a plate that is undergoing cruel and unusual punishment.

Gerald

Gerald- thanks for the advice; I’ll contact bunting and see what I can turn up.

(5:1 says A&V was probably sourcing it from bunting?)

I wouldn’t bet against that!

Gerald

Just run my first job on my newly acquired Heidelberg Platen - very fine halftone drawings.
Bought a lump of engineering grade Al 6061 T651, 9” x12”.
Could only get it in 25 mm so a friend ran a lathe over it to bring it down to 22.37mm. Worked perfectly with KF95 plates. Total cost NZ$100 - around US$80.

Moana Press, that’s great! Can you post photos?