Belt sander for cylinder head planing?

[ebinmaine 67,465]

We've been hand planing our cylinder heads using sandpaper taped to a piece of flat steel for a few years now.  Anybody who's ever done one can understand how tedious that is.

I'd say we probably used that method half a dozen times or so.

Takes up a minimum time 30 to 45 minutes... Often longer.  

Probably half of the ones we've done I thought to myself that I ought to have a belt sander big enough to mechanize most of the work.

Looks as though most or all of the benchtop 4x36 belt models could do the trick. I would lean on the inexpensive side for sure but don't want garbage.

 

Anyone use this method?

Any hints tips tricks?

 

Any recommendations for or against a particular type of sander?

 

 

 

@Greentored

[elcamino/wheelhorse 9,297]

I would be afraid that a belt sander would eat too much material or giving you uneven surface. My experience is based on my wood working and other jack leg projects. Even the finest belts 150 to 200 grit will eat up a surface.

[ri702bill 8,318]

Oh, Boy!!  Kind of like watering the flowerbed with a fire hose. I think it would be too aggressive, too much material removal too quickly -and a great chance to end up tapered but flat. And, you still need to dust a guide coat of paint on to see if it "flat"

Add this one to the list - guns and Tequila allow you to make regretable mistakes in the blink of an eye....

Bill

Edited December 29, 2022 by ri702bill

[ebinmaine 67,465]

5 minutes ago, elcamino/wheelhorse said:

I would be afraid that a belt sander would eat too much material or giving you uneven surface. My experience is based on my wood working and other jack leg projects. Even the finest belts 150 to 200 grit will eat up a surface.

 

3 minutes ago, ri702bill said:

Oh, Boy!!  Kind of like watering the flowerbed with a fire hose. I think it would be too aggressive, too much material removal too quickly -and a great chance to end up tapered but flat. And, you still need to dust a guide coat of paint on to see if it "flat"

Add this one to the list - guns and Tequila allow you to make regretable mistakes in the blink of an eye....

Bill

 

 

The machine shops in this area use a belt sander to plane heads with 220 to 400 grit. 

It costs too much time and money to set up on a milling machine for something that can be done in just a few minutes.

 

I would use a finer paper and turn the head 90° every pass or two.

 

FINAL FINISH would still be done on a FLAT surface.

[oldlineman 1,481]

If I had a not so good head for a test run that is what I would try Eric. Bob

[Pullstart 62,849]

I used to work at a tool and die shop in my younger days.  They had a 24” wide belt with a good quality fence.  I had done a couple automotive heads with great precision on “government time” like lunch, or after my shift.  I’m not sure I’d go for a 4” belt, they tend to wear and stretch quick enough, you could get a curl or wave in the belt sooner than you know.  8”?  Sure.  

[pacer 3,169]

I too would think that method would be .... risky? in a home shop set-up. The machine shop I used had a 36"  ---- flat stone? (looked like) in what appeared to be a - typically - in a shop, a precision machine that was probably very expensive.

 

I have a 12" disc sander for wood work and have used it MANY times and have found all too many times that what I thought was a 'flat' surface, wasnt. It is pretty easy to get a 'flat' surface, but all too often there will be a --- 'taper? And, as already mentioned there is the problem of too much .... aggressiveness.

Edited December 29, 2022 by pacer

[ebinmaine 67,465]

10 minutes ago, Pullstart said:

 8”?  Sure

I agree in principle but I'm not spending thousands of dollars....

 

 

3 minutes ago, pacer said:

'taper? And, as already mentioned there is the problem of too much .... aggressiveness

 

Incorrect taper is definitely something I've thought of.

Best I can do on that is rotate the head every pass or two as stated above. That creates an even wear pattern.

 

Wouldn't the aggressive nature be solved by using a finer paper?

 

[pacer 3,169]

2 minutes ago, ebinmaine said:

solved by using a finer paper?

Oh definitely! I would think ..... 500 grit or more, If you can find it. I know wood paper for my disc tends to be pretty course, though I have never pursued finding any fine grit.

[Pullstart 62,849]

Might just as well keep the oil changed in your elbow I’d say… if you were doing one a week or more I’d understand.  2 a year on average, I’d push it around a paper myself.

[ebinmaine 67,465]

6 minutes ago, Pullstart said:

Might just as well keep the oil changed in your elbow I’d say… if you were doing one a week or more I’d understand.  2 a year on average, I’d push it around a paper myself.

 

I have at least 10 cylinder heads to do in the next couple years.

 

One of the reasons I want to go mechanized though, is I have at least two cylinder heads that are pretty badly warped and it takes two or three hours or more over the course of several days to hand plane one that bad.

 

Also, I'd like to get a little more squeeze out of the k341 heads and to do that you chop off .030 or .040. 

 

I'm not necessarily looking to get the finalized surface on a belt half the width of the head. 

I'm trying to get a lot of the bigger work done then switch over to a known flat surface for the final few thousandths.

[Pullstart 62,849]

Wanna pay shipping?  I’ll get ‘em milled close for you…

[Mickwhitt 4,621]

A belt sander or linisher would not be my choice of weapon.

 

Our mower shop guys never used anything but the aluminium oxide paper glued to a flat board for truing heads.

 

I had a surface grinder which had a vertical cup shaped wheel that was made for truing gasket faces and was big enough for a mower head. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[pacer 3,169]

4 minutes ago, Mickwhitt said:

surface grinder which had a vertical cup shaped

Yeah, a surface grinder would certainly do it nicely .... but thats getting back to the - already mentioned - precision tooling used by the shops.

 

EB, If you wanna give it a go - and I can understand your motivation! - rig up a -- jig? or similar (old head?) to experiment on.

[formariz 11,987]

The biggest issue with that method is how pressure is applied. By hand it is a very difficult thing to do correctly. There is always a tendency for more material to be taken out at the edge the belt rotates towards. With very fine grits, heat also becomes an issue. A flat metal or glass plate is a constant non changing reference area regardless of pressure unless one is reckless at it. Without it such a reference area would really be the pressure applied since one cannot depend on the sanders plate to do that on an inexpensive machine. They are just not accurate. Fine paper will also get clogged quickly without lubrication which can wreck havoc on a machine not designed for that. I experimented with that method to flatten backs of wide plane blades 2" to 3" in width. They were of course high speed tempered steel or similar. Too much of a hassle and they did not come out flat. Far from it and uneven in thickness. Spend more time correcting the results from the sander than it would actually take by hand on a flat plate which always resulted in predictable accuracy.

[SylvanLakeWH 25,555]

No expert, but I'd stick to hand work myself... wax on ... wax off...

 

 

[ri702bill 8,318]

2 minutes ago, SylvanLakeWH said:

No expert, but I'd stick to hand work myself... wax on ... wax off...

 

Aye!!

[ebinmaine 67,465]

53 minutes ago, Pullstart said:

Wanna pay shipping?  I’ll get ‘em milled close for you…

I'll bet I'd be into that. I'll send you a PM later.

[lynnmor 7,305]

There is an engine shop in my area that has a special horizontal belt sander made for truing heads.  I took a pair of 350 Chevy heads there to be dressed after he said how flat they would be.  When I picked them up, I laid them face to face and you could have read a newspaper between them.  He then set up the big mill and did them right but of course more material was removed than I wanted.

 

A belt sanding operation will be no better than the platen backing up the belt and may be much worse.  I learned my lesson. For my small engine heads, I use the sandpaper placed on a very flat band saw table, If a head is way out I have a mill.  Those that use glass should be aware that all glass isn't flat and thin glass will bend to fit the underlying surface.

[John2189 452]

Another trouble with a belt sander is that it would be too fast. You could slow it down by changing v belt sheaves. 
 

Most sanding belts, the splice where they are put together is not smooth so that could cause a problem. 
 

id stick to doing them by hand. 

[953 nut 55,216]

I have two 6" belt sanders, one in the wood shop and one in the horse shop for metal. 80 grit is about the finest belt I can find and I have only used it for aluminum once, It clogged the belt so badly I had to toss it. I do my Engine heads with wet/dry paper (100, 220, 400) on a piece of 1/4" glass shelf and wouldn't consider going near the belt sander with them.

[Mickwhitt 4,621]

Thought I had a piktcha of the beast somewhere...

 

Ten inch ring wheel is enough for most jobs.  Very fine feed in it so you can take off very small amounts. No belt issues that have already been mentioned. 

 

wish id kept hold of it, but it went to a better home lol. 

 

[squonk 41,099]

13 hours ago, 953 nut said:

I have two 6" belt sanders, one in the wood shop and one in the horse shop for metal. 80 grit is about the finest belt I can find and I have only used it for aluminum once, It clogged the belt so badly I had to toss it. I do my Engine heads with wet/dry paper (100, 220, 400) on a piece of 1/4" glass shelf and wouldn't consider going near the belt sander with them.

Jungle site has 400 grit 6" x 36" and 48"

[ebinmaine 67,465]

1 minute ago, squonk said:

Jungle site has 400 grit 6" x 36" and 48"

I purchased sandpaper for Wheel Horse steps from a company called Empire Abrasives. They show all KINDS of neat stuff on there.

[CCW 1,295]

Here's a thought that might enjoy an experiment.  Take a random orbital sander and glue a flat steel or aluminum plate to it big enough to hold a full sheet of sandpaper of your chosen grit.  Clamp sander in place and bring the head down on it.  There are random orbital sanders that allow you to select the operating speed.  Not being at home I cannot take a look at my RO sander to brainstorm any further.