Monday, July 8, 2013

Window Frames Steering Cabin

                              Window frames Steering Cabin

Last big project is to replace the wood of the steering cabin window frames.
All wood at the bottom side where it meets the GRP is rotten away or damaged by water ingress.
Holes can be seen for example where the front part meets the side parts.

The first part was to make the curved bottom window frame which was done the same way as earlier described for the main cabin bottom window frame.
Two 12 mm planks epoxy glued together in the correct shape.
This two glued planks were left for several months due to the winter strapped to the original window frame to prevent that the new glued planks would lose its curve.
When removing in a later stage the original plank it showed that the piece was made out of 4 pieces, thinner planks than I used which would have made it easier to get the correct curve. When fitting the new plank I had some trouble fitting it and getting the correct curve and roundness.

Since the windows were still in the frames and were difficult to remove and since I did not want to take the risk to damage them, crack them, it was decided to use the multi tool and cut the old frame loose from the actual glass of the window.
And in a later stage remove the kit/glue and rest pieces of wood of the actual glass.

During the cutting of the wood it became clear how bad the condition of the actual window frame was it fell apart into different pieces

When the bottom window frame was removed the support mounted on the deck remained in place, this part as expected was rotten as well.
The good thing is that this part is mounted from the top onto the GRP deck which runs from outside to inside, removing the wooden plugs gave me access to the screws.

To be able to shape the bottom forward window frame it is needed to install first the two support pieces onto the deck, which had to be made new as well.
First attempt was to shape them out of one piece careful measuring and shaping the new piece resulted that it did not fit, not even close. Even with further shaping the new piece did not even came close. This mainly due to the round curve which is under an angle as well as the roundness of the deck with a sharp kind of roundness at the edge of the window frame at both sides.
Second attempt was to laminate different layers of wood mahogany together thickness used was 10 mm. The planks of 10 mm were shaped into the same roundness and approximate angle of the support with the deck. The first two layers of wood were glued and screwed together onto the deck with blocks under the wood high in the middle and smaller blocks to the side this way compensating for the natural way of the wood, straight plank, when the tension would be released.

After the two first planks were set they were removed and a jig was made on another plank with higher blocks under the two first glued planks which were glued together to keep the correct curve.
The first two planks were screwed onto this jig at the points and then each day another plank was glued and crewed onto the earlier installed plank.
In between the the fitting of the planks screws were removed.

Not only the bottom part of the front windows was rotten away but also the bottom part of both side windows a screw driver could be pushed with ease through the wood.

Rotten wood was removed at one side to make sure that from the other side if required additional measurements could be taken to get the original shape back as original built, although difficult since from both sides on the same place the wood was rotten away.

From the side window the complete bottom piece was removed as well. It was not completely rotten away but in view of the difference in color which would show after repairs have been made with an insert it was decided to replace the complete bottom piece.
To make sure that the pen (pen and hole construction) of the aft part which runs from the top window frame to the bottom window frame remains intact the wood from the bottom window frame was cut away with a multi tool  before the bottom window frame was removed. The extra wood was then removed from the actual pen so that when the new bottom piece would be installed the same strength would exist as before the repairs, pen and hole construction.

When the bottom piece was removed it was noticed that the support wood for the bottom window piece was also rotten at the front. Also this piece is mounted from the top onto the deck and was removed untill the point that solid wood was found.

When the wood was removed access was available between the two GRP pieces and the gap was cleaned out ,thickness of both parts reduced and the gap was closed with a glass fiber math and glass fiber two component epoxy.

New support piece made for the side window, not mounted to the deck yet since the plan is to paint the deck in way of the new window frames before these are mounted.
The wood is kept higher to be able after installation to sand it flush with the original still installed support plank for the bottom window frame.

The deck house is supported and measurements have been taken before all window frames were removed from the sides and the front, one side of the frame remained in place, port side, until repairs have been completed at starboard side and the front windows.

Next step was the sand the deck in the way where the new window supports would be fitted. Deck was sanded inside and outside, inside was pretty simple no new paint coats were used in the 40 years of service but outside at least 4 coats needed to be removed before the original GRP deck was reached.
At the same time the holes in the deck were closed as well some groves from old sanding of the deck with two component glass fiber epoxy.

When all was smooth the new front window frame supports were mounted onto the deck.
After the installation the angle was checked between the deck and to be installed new window frame, although carefully made the angle was too steep and the new window frame supports after mounting them onto the deck. They were sanded into the correct shape and the angle was checked regular.
The correct angle was taken from the removed pieces.
When the correct angle was reached both pieces were sanded to the correct height, as with all pieces like these I find it rather difficult to get them in the correct shape, therefore I make them over sized which gives me the opportunity to sand them to the correct dimensions.

When the angle was to my satisfaction the new window frame was temporary mounted against the new supports although it looked when holding the new frame in front of the new supports that the shaping was not even close, it showed that when the new frame was mounted against the supports that the frame was correctly shaped. What I learned is that new curved and round parts under an angle should be regular fitted and not only hold in place but actual mounted, with clamps for example, to make sure that not to much wood is sanded off on side while it might not even be required.

The deck , one side and front were sanded smooth high spots of the repairs removed and was coated with a two component white paint. At the points were the new window frames would be installed two coats were painted.

The next step was the fitting of the new parts onto the deck house, at starboard side one side frame at the bottom and one side frame at the front.
Although this looks not to difficult after all new parts were measured and copied as best as possible from the removed parts it came to me after more than one day fitting that this method might not have been the best approach.
Eventually all fitted to my satisfaction.
What I did regular during this fitting was to position the window glass on the front side frame to make sure that the angle of this part of the wood was in the correct angle.
This could be easily measured from the window to the edge of the wood this should be a straight line in parallel with the window glass.

When fitting the new front bottom window frame it not only took a long time to get the correct fit but I also noticed every time it looked like that the angle changed as well as that at a different point the wood needed to be sanded to get the correct fit.
The trick is the every time the frame is positioned for checking the fitting of the wood onto the deck that it needs to be clamped into position. One can than exactly see  if the fitting onto the deck is acceptable.
When the fitting onto the deck in the center is correct and the new plank is not completely in position at the sides a gap will be seen at the sides.
At the same time a mark has to be made onto the plank and the deck to make sure that the position is every time the same. One can see in the second picture that when the new window frame is not clamped onto the support that the plank sticks out above the deck which gives the impression that the fitting is not correct.

All new parts where than removed again and the supports were sanded smooth and coated with two component epoxy to protect them against weather. The same with the inside window frames.  Second step was to lightly sand the coats of epoxy and then coat the planks with two layers of varnish.

The inside side support which was rotten was removed and replaced by a new piece of wood, also this part was coated in epoxy to prevent future water ingress.
This part was also screwed from the top onto the deck.
New piece were visible inside was slightly sanded and coated in two layers of varnish.
The reason for all parts which are visible from the inside to varnish them is when they are installed that no painting is required which will also prevent that the new painted deck will have the chance of varnish stains.
The new part was screwed onto the deck and glued at the bottom with Sikaflex Seal and Glue to close any gaps and prevent water ingress.

For the other side it was decided first to make the new parts fit onto the old structure, this showed to be a major time saver, better fitting new onto old and replace them one at the time.
First part fabricated was the front side part of the front window.

Next step was to fit the new front side window frame with the first new piece.

Then the bottom window frame was removed and a new one fitted

As mentioned before this system worked quicker than the first side which I did with taking measurements removing all old wood and making new parts and then try to fit them together.
As the next picture shows it became like a 3 Dimensional puzzle.

Since I wanted to keep the boat the same as per original design and to be able to take the steering cabin off, I have been searching the web for a new rubber seal between the steering cabin and the deck house I have found one which is close to the original.
Same thickness as the original one only a round edge instead of a more or less straight one at the bottom.

With the window frame removed it was now also rather easy to sand and varnish the steering console which normally is rather difficult to the limited space on the side and difficult to reach at the front side.

Next step after I was convinced that the fitting of the new wood pieces was correct to place the rubber onto the side planks which are placed onto the deck house. I used the same method as original and stapled the rubber onto the wood, bear in mind the wood where the rubber is mounted against is protected with two component epoxy.

Then one side was in my case ports side was mounted onto the deck and glued with colored two component epoxy in place , this was the complete side window frame. I used a very small amount of sikaflex between the support of this plank and the GRP of the deck house just in case when there is water ingress to prevent that it will enter the minor gap between the GRP of the deck house and the wood.
The next day the other side was installed and glued in place
The third day to front window frame was installed and glued in place.
This took quite some time the plank being slightly under tension and fitting it into the two side pieces.
The plank was screwed against the inside supports and clamped where required to get it exactly in place.
In a later stage the screws were removed and the original bolts and nuts were installed.

Next step the whole construction was sanded to remove the epoxy which came out between the different pieces.

After the sanding the actual glass windows were held in front of the new construction and the outer dimension of the glass was drawn onto the wood. Then a second line was made which was the height of the inside window frame 10 mm high.

The wood excess, more than 10 mm was now cut of with a small circular saw with laser point.

The next step is to follow the wood with a router of 10 mm to create the space where the actual window glass will fit in. As can be seen from the next picture this creates a lot of wood particles throughout the boat.
The corners where the old and the new wood were connected and which could not be reached with the router were sanded with a small round sanding device which was mounted on a Dremel tool.

The glass is test fitted and checked if there is enough space between the glass and the wood to make it able for the wood to expand and shrink without bringing the glass under tension.
When all is acceptable, the groove where the glass will be placed in is protected with two component epoxy.

The next step will be the fitting of the actual glass and creating a water tight construction for the sliding windows. This will be explained in the next update.
But first all will be sanded inside and outside since now it is rather easy to reach all wood of the steering cabin with all windows removed.

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