HR, Malo or Najad windscreen/extrustion

fearmhuir

Member
Joined
7 Nov 2017
Messages
83
Location
Bangor, Co Down
Visit site
MALO 36, YEAR 2003, DEALING WITH WINDOW CORROSION


In 2018 I tackled corrosion on the aluminium screen on my Malo. The corrosion was entirely along the bottom fixing rail, and in particular around the roots of the vertical aluminium struts.

I have always had a little pool of water inside the screen, just where the glass ends on each side. My theory is that seawater leaks into the bottom rail extrusion, and sits there, eventually corroding the bottom of the vertical supports and eating the aluminium from the inside,


So, here is how I tackled the job. I did it alone, but ideally you should have two helpers when reassembling, particularly when putting the top rail back on.


I did have high definition pics on a camera, but these were deleted at some stage, so the photos I have are just phone ones, but they give an idea of the process.


Here is what the corrosion looked like:

SfOC6pFDa_OnMkklvEwaUN_EcJiGsyfJY7wbaaBZb9QBoG2w1U4KGze58mB0WCnUWFkMIXOKyqe6ST5pd_ud9bskA6Ac0dcJ8G2xV7Xj2LHk6-joX4BB-nUtAcWXhzpb-PiHQQfg=s0



Before I started I soaked all the screws at the top and bottom of the upright struts, and also the two at the very back of the screen. I applied penetrating oil regularly for about two weeks.


I was lucky and all the screws came out fairly easily - the two at the back of the top rail were difficult but eventually shifted.

With all the screws removed, tugging at the top rail eventually freed it. I started pulling at the left and right corners of the middle pane.


3uKQZYhzaW__v2K0ttTJo9lsMIkD4PN2V5DS3EP4SyEB0h3dbndSukxvUCTnACuPHVV95aLTuFxaMv_9j7drBTDG7Pwbwt0c4dQvL3N16TcMEtGK5D6WXaIvNmDiiF2P_Wi1KyyU=s0



Then I removed the front pane of toughened glass using ‘glass handles’ as shown. It takes quite a bit of tugging to get the glass to initially move. I eventually had to resort to putting a piece of wood on the glass for protection, and then tapping the bottom of the glass handles upwards. With the top rail off, the glass assembly can be moved outwards and backwards, which helps unstick the glass from the seal.


LdhSPpfGjk6xQgXfH3X3DG1IjbqhmOZGNJMvOA5OBhDvNys7tECR-tTG85vr5kYEeaCEcga8ZPRZ6qChYmVDq50bOKx-cC0HYxZj4ybBotqLKjAdv4Y-croNTFilIMj-tko7WlPa=s0



When the glass gets to this sort of height, you can push the window uprights outwards a little, drop the glass down, and it will then come out.

After that, it is an easy job to dismantle the rest of the screens and supports.


LRKjCN_Lro5H_R-bvUk9U1wKXgXeUg6OkIh2i7RSti3VRGmePRt70BcHpC9AHBRRmR5OLuhQogEPFet3Sxr7K97dGhORghLaY4GQhsbmY7gxcXETtEwPxbo7Da1LUYAm_hmoR405=s0



Once everything was dismantled, it was time to remove the corrosion. For this I used a fairly large high pressure washer. I held the nozzle around two inches - yes, that close - to all the corroded parts and gradually it removed all the white corrosion, leaving grey aluminium. In my case the bottom rail had not corroded through, but there was quite a bit of corrosion inside there, and also at the bottom of the screen uprights.

I then dried everything off well, using a hot air blower to speed up the process.

I maked everything off, and applied two coats of Halfords aerosol etching primer, followed by two coats of aerosol silver paint (Hammerite I think).


_ETjwqQFEqYb88FTk3PGawOeq9PC3XUANx3zX_h4wMFUCNAaQyJ-EyhizkSstx0BVNQRZbS3mAnrxiZWgVXu-IxKxeF2bWTAlLbObgT3bmX9ojIiFYbaSVRchh5Zu-Zww5DH2rzN=s0



I cleaned all the rubber seals well with a green Scotchbrite pad, and dried thoroughly.


In order to stop salt or fresh water lodging in the bottom channel, or leading down onto the bottom of the uprights, I decided to completely fill the channel with mastic. I used black Tec7 for this.


So, starting at a back panel on one side, fill the channel fairly full of mastic, and then fit that seal and window. Then move to the other side back panel, do the same, Work forward, left and right, finishing with the centre panel.


To fit the glass and rubber seal to each section, you have a choice of two methods:

  1. Fit the seal to the glass and then press the glass and seal down into the sealant until it pops down into the channel completely.
  2. Press the rubber seal into the sealant until it is fully down in the channel. Then, using two pieces of plastic (I used two pieces of Formica laminate) press apart the lips of the seal and force the glass down into place.

I started out with method 1, but found that the seal was prone to pop completely down into the channel and had to be prised out, and the channel refilled to start again.


Whatever way you do the assembly, you need to mask EVERYWHERE. Tape each side of the bottom channel, and then put cloths or plastic sheets everywhere, even over the arch.

No matter how careful you are, mastic gets everywhere, including you.


Once you have all the glass in, if you intend leaving the assembly to take a break until the next day, make sure to loosely fit the top rail, without the rubber seal, over the tops of the glass. This will keep the panels at the correct angle while the mastic cures.


As I had no corrosion on the top rail, I fitted the seal to it, and starting at one end, using the Formical, persuaded the glass between the seals. I lubricated the glass with some lanolin I had handy, but would have used silicone grease if available.


The top rail is where you really need help. As you work your way along each glass panel, there is a tendency for the rail to pop off the glass at a place you have done earlier, and then it is back to square one. One person to hold the rail down after you as you work your way along is ideal. Someone working at the glass at both sides at once helps too.


So, that is how I got on with my screen, and to date, I don’t have any corrosion after three years, so fingers crossed for the future!


The screen on my Malo is an OMetall one, and Malo switched to them for a while, but switched back again after a few years! I had the pleasure of dismantling a Hallberg Rassy screen quite a while ago to replace a broken glass, and the whole assembly had mastic filling everywhere. So, that is part of the issue with these Malo screens, no mastic, so water lodges, but also the aluminium or the anodising is not up to scratch for marine environment.


Good luck with your endeavours, and if you have questions, please message me!


Richard - Helvick - Malo 2003
 
  • Like
Reactions: pvb

willowcarroll

New member
Joined
22 Sep 2012
Messages
18
Visit site
Richard
That is very very impressive work and those photos with attached instructions give me a very clear plan to follow. I am much obliged . On anchor off coast of Istria now and back ireland late October . Have a bit of work ahead of me in the interim though ! Than k you indeed regards .
 

pandos

Well-known member
Joined
15 Oct 2004
Messages
2,835
Location
Ireland, (Crosshaven)
Visit site
Richard.

Great write up. I have an old hr352 with a problem screen, ( I have notions of a hard dodger might replace screen completely) the 352 is not much smaller than the Malo 36. But I am amazed at the height of your arch arch /main sheet.

Is it actually high enough to stand under or is this just deceptive photography?
 

pvb

Well-known member
Joined
16 May 2001
Messages
45,605
Location
UK East Coast
Visit site
I have an old hr352 with a problem screen, ( I have notions of a hard dodger might replace screen completely) the 352 is not much smaller than the Malo 36. But I am amazed at the height of your arch arch /main sheet.

If it's just the rails which fix the screen to the GRP, you can still buy new ones from HRParts. I replaced them on my HR352, not especially easy, but DIY-able!
 

pandos

Well-known member
Joined
15 Oct 2004
Messages
2,835
Location
Ireland, (Crosshaven)
Visit site
If it's just the rails which fix the screen to the GRP, you can still buy new ones from HRParts. I replaced them on my HR352, not especially easy, but DIY-able!
Thanks for that info, but mine is already a mutant... I have the screen raised on teak strips to allow organisers to fit directly underneath and thus all lines lead back along the coamings to clutches, so I can reef hoist etc whilst sitting at the wheel... And the tables near the companionway are kept clear...

Last year was dedicated to function.. ...engine rebuild, new rigging, steering cables, thruhulls, seacocks, new radar, plotter, etc etc . This year it's going to be prettiness...varnishing grp repairs and making the screen either respectable or replaced with hard dodger ..(.."I really want to cut the doghouse up and make the boat into it a deck saloon but so far I am managing to control these impulses with alcohol and thoughts of resale value of 500 euros....)
 
  • Haha
Reactions: pvb

fearmhuir

Member
Joined
7 Nov 2017
Messages
83
Location
Bangor, Co Down
Visit site
Richard.

Great write up. I have an old hr352 with a problem screen, ( I have notions of a hard dodger might replace screen completely) the 352 is not much smaller than the Malo 36. But I am amazed at the height of your arch arch /main sheet.

Is it actually high enough to stand under or is this just deceptive photography?

I am 5' 9'', and I bump my head a little bit, so it is about 5' 7'' maybe? A hard dodger would be nice, but be careful - on the bigger HR models that were supplied with a hard dodger I have an idea there were modifications to the hatch and maybe cockpit floor level? A HR48 owner with a hard dodger said that to me?
 

pandos

Well-known member
Joined
15 Oct 2004
Messages
2,835
Location
Ireland, (Crosshaven)
Visit site
I am 5' 9'', and I bump my head a little bit, so it is about 5' 7'' maybe? A hard dodger would be nice, but be careful - on the bigger HR models that were supplied with a hard dodger I have an idea there were modifications to the hatch and maybe cockpit floor level? A HR48 owner with a hard dodger said that to me?
You are correct about the heights, they made a hr352with a hard top but no passageway to the aft cabin and as far as I know the cockpit resembled a rasmus 35...

The height would not allow standing but ideal height for sitting with your feet dangling into the cabin...

I see it just as a solid spray hood which would allow me to put on handholds speakers lights etc..and have a more permanent solution to canvas ECT.

There is an article online about a guy who made a solid dodger in the shape of a sprayhood mounted on top of his screen...

I may follow his lead....

How to Build a Hard-top Dodger
 
Top