Sliding Hatch - Track Improvements ?

[Leeward Rail]

Evening all !

I'm in the process of refinishing/ varnishing the teak on our 1987 C22, including the rails that the main hatch slides in.
The fiberglass hatch itself has cracked and has damaged coring.

Since i'm doing this, I figured I should improve them.
The edges of the hatch, which slide in the slots in the teak rails, will obviously need to be built up a bit with glass.

Any cool ideas on improvements ?

Line the slot in the teak with an aluminum extrution ?

Bond some plastic of some type to the bottom of the slot as a nice glide surface ?

Use a couple layers of clear epoxy in the slot, before I apply the varnish ?

 

[fred1diver]

if you can find something like this, it's really slippery
http://www.leevalley.com/en/Wood/page.aspx?p=32045&cat=1,43455,43831&ap=1
would make some good sliders

 

[jssailem]

Not sure about your specific issue, but I have found that a good cleaning can work wonders. You might find grit is the issue not the slipperiness of the slot. Additionally you may find that the teak slot gives just enough tension that the hatch can be partially opened and it stays in place. I cleaned and waxed a hatch slot only to discover it slid all the way open or all the way closed and nothing in between. Got used to it but it was nice to be able to have it partial open at times.
I got more than I bargained for with my cleaning.

 

[Leeward Rail]

if you can find something like this, it's really slippery
http://www.leevalley.com/en/Wood/page.aspx?p=32045&cat=1,43455,43831&ap=1
would make some good sliders

Good find. I didn't know Lee valley had something like that. I'll have to take a look next time i'm near the store.
There's a local place called "pal plastics", that sells plastic offcuts for cheap, but that Lee valley price is good @ $15

 

[Leeward Rail]

Not sure about your specific issue, but I have found that a good cleaning can work wonders. You might find grit is the issue not the slipperiness of the slot. Additionally you may find that the teak slot gives just enough tension that the hatch can be partially opened and it stays in place.

Interesting point ! I hadn't thought of that.

I'm not really having an issue per se.
The hatch was hard to open, but that was due to the cracks and wood core swelling.
Once the hatch is repaired it should be like original.

One thing that has happened over time, is the wearing thin of the fiberglass hatch edge that fit in the slot.
I plan on repairing it with fibreglass, but have been musing about a more robust way of fixing it. Preventing deterioration of the glass and teak by reducing friction was one idea.

 

[Texas Gun-Man]

if you can find something like this, it's really slippery
http://www.leevalley.com/en/Wood/page.aspx?p=32045&cat=1,43455,43831&ap=1
would make some good sliders

It's funny. We use this to build total hip and knee replacements. You are absolutely correct it is slippery!

 

[Texas Gun-Man]

This site has UHMW in odd shapes if any of these strike your imagination.
http://www.usplastic.com/catalog/default.aspx?catid=868

 

[CloudDiver]

Lee, the problem with putting UHMW plastic into the teak slot, like an insert or something... practically no glue will bond to it. Mostly you have to melt it together with special plastic 'welders'. There are some specialized glues but they are extremely expensive, very nasty, and mostly not available to the general public.
Putting sone epoxy in the slot, after sanding it clean, is probably the ticket. For the edges of the hatch that is worn thin, glass it if you like but its not necessary... just build up a tape dam and pour four pumps of epoxy on each edge to thicken it. Stingy Sailor did this, there is a write up on his page. I also have some pics doing the same in my thread. With some epoxy in the rail slots and thicker edges it'll slide like butter... maybe add some wax.

 

[Gene Neill]

You may be surprised how much easier the hatch slides after you do your repair on it. I know I was. Easy enough the wind opens it while being towed, if I don't put a lock in the hasp.

 

[Leeward Rail]

Luke, interesting. I'm guessing that people use mechanical fastening when they use UHMW for woodworking tools.
I'm likely going to do what Gene did with cloth, because of the cracks and other damage. I'll make that decision once I get into it.

Using something additional in the slot would limit how thick you can build the hatch lip, unless you widened the slot. I've been reading the various threads I could find, including Stingy's and Gene's and i'm now leaning towards simply putting some epoxy in the slot in the teak.

Options that people used in threads here were:
Teflon tape OR fuzzy half of velco face down on hatch lip
90 aluminum extrusion to both rebuild and reduce friction

I figure that the extrusion is a bad idea in my case, since I need to repair the hatch itself anyhow. Why make more work ?

Fuzzy Velcro seems like a bad idea, since it would gather and hold grit, which would just hasten deterioration and inhibit cleaning rinsing the slot occasionally.

Teflon tape is likely an option, if needed, after the hatch is back in use, but judging from what you guys have all said here, on in other threads, it simply not needed if the hatch lips are built back up again.

Thanks all !

 

[Justin_NSA]

I can tell you what NOT to use. The plastic (Teflon?) tape woodworkers use on table tools to make them glide easier. I tried it on the Mac sliding hatch and it didn't last a season before the sun turned it yellow and brittle. I had considered next using strips of aluminum if nothing else to stop the wear on the deck, but I sold her before I tried it. IMHO, fiberglass should not slide against fiberglass. Dirt will act like sandpaper over time and destroy the gelcoat.

 

[CloudDiver]

Lee,
I would just brush two coats of epoxy into the rail slot, it won't thicken up too much. I'd recommend removing the rails, sand completely clean. Then brush the entire rail with epoxy for two coats, hot coat so you don't have to sand. Then when fully cure, sand with 120 grit and apply Epihanes varnish, at least 4 coats. You can apply the varnish without sanding between coats as long as you don't let each cure for more than 12 hours. In the right temps/humidity you can get follow on coats done within just a few hours of each other. You don't have to put the varnish inside the rail slots, but it wouldn't hurt on at least two of the coats. The slots are mostly protected from sunlight, but from the sides they could get some UV. Just keep in mind it takes weeks for the varnish to reach full hardness. The rails will look great for 10 years.
When you repair the hatch lid rails with cloth, it won't add that much thickness even if you use 3 or 4 layers of 6 oz tape. When I did 4 pumps of epoxy I only thickened it with colloidal silica just enough to still be liquid and self level. that added more volume so they were too thick, but I just hand planed them and sanded them. The slots on my new plastic rails are .275, and I got the hatch lip to around .250 to .260, I checked with calipers.

 

[gjordan]

This is a good thread. I am going to start on the same project next week. I dont expect any problems with the wood rails, but the lip on my hatch has about a 2 inch crack at the aft end. Epoxy (magic) and a couple of layers of thin cloth and I think I will be back in business. I am glad I have read this before I start. ____Grant.

 

[Leeward Rail]

@gjordan

There are more than a few threads on repairing the hatch on a c22..

Gene's thread with him building up the edge with cloth:
http://forums.sailboatowners.com/index.php?threads/sliding-hatch-lips-cracking.163095/

Stingy's post where he uses epoxy
https://stingysailor.com/2014/02/21/permanent-main-hatch-repair-2-2/

My original old thread (i'll be posting my hatch repair progress there)
http://forums.sailboatowners.com/index.php?threads/reparing-the-main-hatch.176819/

Thanks for the ideas and input everyone !

( I wish i had admin rights so i could merge this thread with other relevant threads. I forgot that I'd asked similar track modification questions in my old hatch repair thread.)