Shortening a bow roller / cuttiñg stainless steel or is it chrome!

[Zagato]

I wanted to chop the end off my bow roller to shorten it and re position the actual roller further back. It is not made from Aluminium but looks like chrome so I presume it is polished stainless steel. The welds are also shiny so I wondered if it is actually just chromed steel. Chrome on my car does not last five minutes so I am amazed if it is chrome how well it is lasting. That would be a PITA as I would then need to get it re chromed unless i bodge it somehow for now being on a budget!

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[northwind]

Most likely stainless steel. Have you got a magnet? See if it sticks, if it doesn't then stainless.

 

[rogerthebodger]

Will not be chrome steel. If it is chrome would be brass but again as you say it has welding would not be brass. Most likely polished stainless steel.

You can cut stainless with a steel or better stainless steel cutting disk on a small angle grinder. You can also get sanding and polishing disks to clean up and polish the cut edges.

The issue you may have is drilling the holes for the bow roller and the chain captive pin if fitted.

Post a pic so we can see exactly what is needed.

 

[Zagato]

Many thanks. I cannot put pictures up on this forum but have a picture up on the Sailing and cruising group on Facebook. Somebody on their has also said it is Stainless Steel which is great news and will save me money. I will get some cutting discs ordered.

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[rogerthebodger]

Many thanks. I cannot put pictures up on this forum but have a picture up on the Sailing and cruising group on Facebook. Somebody on their has also said it is Stainless Steel which is great news and will save me money. I will get some cutting discs ordered.

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Post a link then.

 

[Zagato]

Will see I find this works Roger.

https://m.facebook.com/story.php?story_fbid=10158248306224093&substory_index=10&id=100015763741827

 

[rogerthebodger]

Will see I find this works Roger.

https://m.facebook.com/story.php?story_fbid=10158248306224093&substory_index=10&id=100015763741827

Facebook says the link is broken.

 

[Zagato]

Odd works for me... sorry I am not very tech orientated.

 

[rogerthebodger]

Odd works for me... sorry I am not very tech orientated.

May be it my location.

I can get into this Sailing and Cruising

Is this the correct place and how can I get to your pics

 

[Zagato]

It is the sailingandcruisinguk group here...

https://m.facebook.com/groups/1813969098854555/?ref=group_browse

 

[Beneteau381]

I wanted to chop the end off my bow roller to shorten it and re position the actual roller further back. It is not made from Aluminium but looks like chrome so I presume it is polished stainless steel. The welds are also shiny so I wondered if it is actually just chromed steel. Chrome on my car does not last five minutes so I am amazed if it is chrome how well it is lasting. That would be a PITA as I would then need to get it re chromed unless i bodge it somehow for now being on a budget!

Sent from my iPad

You can cut SS easily with a hacksaw, just go slowly and press hard. Use a high speed steel blade, they are usually coloured blue. Drilling the same, slow and hard with some oil squirted on now and again. People think that SS is difficult, it isnt.

 

[Beneteau381]

Many thanks. I cannot put pictures up on this forum but have a picture up on the Sailing and cruising group on Facebook. Somebody on their has also said it is Stainless Steel which is great news and will save me money. I will get some cutting discs ordered.

Sent from my iPad

Be aware that if you use cutting disks, the speed will work harden the SS and make it difficult to hand tool it. Far better with a hacksaw, slow but sure.

 

[Zagato]

Thanks for that, i will have a go with hand tools, files etc for the final bits. I believe you should just use water not oil when drilling SS. Oil is fine for ordinary metal but it just gets too hot and burns away on SS whilst water works a treat apparently!

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[Beneteau381]

Thanks for that, i will have a go with hand tools, files etc for the final bits. I believe you should just use water not oil when drilling SS. Oil is fine for ordinary metal but it just gets too hot and burns away on SS whilst water works a treat apparently!

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Use oil, trust me, if you get it hot enough to burn away you will work harden it. ? I did buy some drills especially for SS a while back, they have weird cutaways on the lands. They do work though.

 

[VicS]

Thanks for that, i will have a go with hand tools, files etc for the final bits. I believe you should just use water not oil when drilling SS. Oil is fine for ordinary metal but it just gets too hot and burns away on SS whilst water works a treat apparently!

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I agree a hacksaw slowly but steadily for cutting

For drilling If you have many hole s to drill invest in cobalt steel drill bits. Other wise have a good supply of HSS bits
Slowly but steadily is the way without pausing. If yu stop it will work harden before you can get going again
Dont centre punch more than very lightly because that will work harden it

You might try WD 40 cutting oil >>>> available from Screwfix WD-40 Cutting Oil 400ml

 

[Neeves]

It will be infinitely better if you can take the bow roller of and trim it at home. If you do it on the boat, specially with an angle grinder, you will have flecks of steel embedded in the gel coat (I assume they come from the discs) which will rust and look less than attractive. I'd use a small; angle grinder, much easier to cut to the lines you want than with a hack saw, especially if you leave it mounted. It will also be much quicker unless you are happy to spend a full weekend simply cutting and filing to shape and then smooth. To drill holes in stainless needs pressure - not easy to achieve if you are doing in situ as when you apply the pressure the flange you are trying to drill may simply bend a bit. I'd be suggesting 'filling the space between the 2 sides, lump of wood, to engender some rigidity.

I'd have to ask - why do you want to make it shorter and move the actual roller back. With the roller 'back' you have a chance of damaging the stem gelcoat when you retrieve - depending on what you mean by back.

You could of course simply remove the bow roller, drill some appropriate holes, apply some reinforcing to the new holes, fill the hold holes and thus move the bow roller back without any need to attack it. Without looking at your current assembly - that's what I'd do.

Jonathan

 

[William_H]

I agree with Neeves don't even consider doing the job on the bow of the boat and especially if it is still in the water. ol'will

 

[rogerthebodger]

Work hardening of any steel including stainless steel is generally caused by cold working and /or plastic deformation.

Polishing stainless does tend to give a harder surface but is quite easy to drill through.

I have never experienced work hardening by abrasive cutting and I have cut lots of stainless steel over the years.

The trick in drilling stainless steel is a sharp drill, Very slow speed and high pressure.

If the drill does not produce chips while cutting (continuous clips is better) stop and sharpen the drill and ensure you have enough pressure.

The tricky point is at break through where it is better to reduce the pressure and be very gentle as the drill can grab and if you dont have the hand drill firmly held it can spin out of your hand.

Unless my supplier laser cut my stainless I always cut with an abrasive disk either in a bench cut off machine or a cutting disk in either my 110mm angle grinder or my 230 mm angle grinder. I alsi us an angle grinder for shaping and initial surface preparation for polishing followed by progressive finer grit flap wheels then polishing mop also on a bench mancine or angle grinder.

This is my bow roller fitting

This may be over kill for your boat but all 3 side lated cutout and polished but angle grinders with cutting, grinding and sanding disks

This will show you some of the stainless that was made some by me some by a friend for my boat.

Distantshaws

 

[Spirit (of Glenans)]

You can cut SS easily with a hacksaw, just go slowly and press hard. Use a high speed steel blade, they are usually coloured blue. Drilling the same, slow and hard with some oil squirted on now and again. People think that SS is difficult, it isnt.

A cobalt drill bit will make it easier. Don't stop drilling until you are through, otherwise the metal will 'work-harden'. I once made the mistake of drilling a pilot hole first then enlarging it with a bigger drill bit. The result was that the hole reduced the diameter of the second bit to that of the pilot bit!

 

[Zagato]

Thanks folks, that is a superb bow roller Roger. I cannot type directly on the forum with my old iPad, it is just too slow and if you make a mistake and press delete it has a tendency to wipe out the whole lot (too many adverts on the site I think) soooo. I have to type elsewhere, copy and paste. I also cannot post pictures. What I am saying is that answering questions is not a quick task. I have answered all the questions on Facebook which is easy to use and shows pictures of my boat ?.

Yes I will be taking the bow roller off. I also need to fit a spreader plate of some kind underneath the deck. Unfortunately the underside is really wavy by up to 1cm. There is not way I am going to grind that back smooth, access is near impossible to just undo the nuts let alone any fibre glass matting etc which is why it is probably a pigs ear and wavy! I don,t suppose anyone can recommend a hard setting filler or solution.

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