Sliding hatch runners

[jddevel]

Advice please. I`ve brass strips fitted as runners on the top of the angled runners my hatch sits/slides on. However as they do not extend right to the outer edge and there is sideways movement on the hatch itself it has resulted in paint wear to these outer edges. So I intend replacing the brass but with what? Wider brass, stainless steel or as some appear to use PTFE nylon. 

[plainsman]

Not stainless steel as all as is not stainless as is hard to remove scratches that will impair smooth running. Not familiar with PTFE runners but imagine it would scour eventually.. I'd go for brass as any scouring or damage can be buffed out. If kept polished brass should not require any form of lubrication to attract dirt and grit.

[ditchcrawler]

I used wider brass and put PTFE on the hatch to slide on it

[jddevel]

Thank you

[Neil2]

We came through some locks with a boat that had nylon runners, the owner had fitted them several years ago and they were still smooth, the slide was effortless to move and I resolved to replace mine (brass) with the same.  I also met a guy a few weeks back that had fitted transfer bearings to his and that worked well too.  

[system 4-50]

I'm no expert but I would have thought desirable to eliminate / minimise the sideways movement of the hatch. Is it as designed or has something failed?

[jddevel]

4 minutes ago, system 4-50 said:

I'm no expert but I would have thought desirable to eliminate / minimise the sideways movement of the hatch. Is it as designed or has something failed?

It`s a new sailaway by Bourne Boats although the existing brass runners fitted by others. I feel that the sideways movement whilst possibly within acceptable tolerances does lead I feel to the edge of the hatch rubbing against the edge of the metal the hatch slides on if not pushed back perfectly squarely and which action would not normally occur unless very cautious about sliding back or forth. It has damaged the existing protective paintwork and as the craft is to be painted shortly I wish to rectify the situation. To that end I have decided to fit and have ordered some 3mm by 51mm PFTE "runners" which I will replace the brass with. Have purchased 4 lengths. Two for the hatch underside and two to replace the existing with.

[system 4-50]

My hatch has 4 short (20mm?) brass rods with slots cut into the ends screwed to the inside of the hatch side flange and which provide the hatch running surface, so quite a small area. The rail running surface is a strip of brass U channel about 10mm each side which is hammered on to the edge of the 50? mm angle iron welded to the roof. Again a very small contact area. I don't know if this is typical.

[Jess--]

my boat has what appears to be nylon runners, presumably original to the boat they have no damage and still slide easily after over 20 years

 

[Cheshire cat]

It looks like on Jess' boat the horizontal wooden piece stops any sideways movement.

[Slim]

11 hours ago, ditchcrawler said:

I used wider brass and put PTFE on the hatch to slide on it

Ditto. A squart of PTFE once a month on the brass runners works wonders

[Jess--]

1 hour ago, Cheshire cat said:

It looks like on Jess' boat the horizontal wooden piece stops any sideways movement.

that and the hatch edges wrap around the runners

[LadyG]

maybe Tuffnel not nylon?

[adrianh]

The black plastic is possibly a grade of oil filled nylon. Will work very well but must only be fitted with 1 tight screw and the others loose to allow for expansion / contraction due to variable moisture levels. A soft wax is a good lub for a hatch slide.

Just interested to know how you are going too attach thin PTFE? By its very nature nothing will stick to it.

If screwed you will only be able to use small ( m4) countersunk screws or similar. Ideally it needs a very smooth surface to run against, ie thin stainless steel strips glued to the underside of the hatch. Never use WD40 as a lubricant as this seriously increases friction with PTFE. Will slide very easily when wet  - in my work I use it a lot in the food industry 

 

 

 

Edited October 6, 2017 by adrianh

[ditchcrawler]

22 hours ago, adrianh said:

The black plastic is possibly a grade of oil filled nylon. Will work very well but must only be fitted with 1 tight screw and the others loose to allow for expansion / contraction due to variable moisture levels. A soft wax is a good lub for a hatch slide.

Just interested to know how you are going too attach thin PTFE? By its very nature nothing will stick to it.

If screwed you will only be able to use small ( m4) countersunk screws or similar. Ideally it needs a very smooth surface to run against, ie thin stainless steel strips glued to the underside of the hatch. Never use WD40 as a lubricant as this seriously increases friction with PTFE. Will slide very easily when wet  - in my work I use it a lot in the food industry 

 

 

 

Did mine the other way up, Brass on the runners and PTFE on the underside of the hatch, that way gravity was on my side, I think the PTFE sheet had a backing on it which I glued to the underside of the hatch lining.