Monday, 18 April 2011

Baked Veneer Hull Repair

I have purchased two timber veneered boards and built one and they all had problems with the veneer cracking. This was due to the veneer drying out and re-sealing was the remedy.  I repaired a friends boards recently that was an extreme case. The board was accidently left in the sun(Australian sun - fry eggs on your car bonnet!) in a board bag hull upward for two weeks! He thought that the board would need to but cut up to fit in the garbage but when I took a look at it I thought it was salvageable.  The saving grace was that the deck was not facing up.  That would have meant a lot more work and a board

Here is how I undertook the repair.

The entire hull was covered in cracks that 
sat up higher than the surrounding area.

The veneer is reinforced with fibreglass in areas such
as the fin box.  These did not crack but the weave
appeared swollen and needed to be faired.

The rail has a fine weave glass for about 25mm from
the rail which is post moulded.  This area may or
may not need fairing also.

Here is the hull after being sanded with120 grit(random orbital).
Be sure just to take of the highs, you dont want to go too
far into the veneer as it is only 0.9mm.

Here is another area after sanding with the120 grit, there are
finer cracks present.  You want to sand until all of the
lows have been just touched by the paper.

Tape off the rail and tail area that is glass covered,
you only want to apply epoxy resin to areas of unsealed
veneer and gelcoat.  Warm the room where the board
is located.  Warm the resin to the recommended curing
temp using spot lights.  When the both have warmed
apply a thin layer of resin and tipoff using a piece of foam
roller or rubber gloved hand.  The board should be cooling
as the resin is applied to stop out gassing under the curing
resin.  If the boar is cooling this will actually suck resin in,
which is a good thing in this case
More info on this step later....
The first layer of resin applied.  Note the patch under the
gelcoat from the factory.  Might have been a defect in
the veneer or a repair done and covered with a glass
patch before final painting .

Edge of the tail patch reinforcing the box lightly sanded
to blend with the veneer.

Detail of the first resin layer. 
There will be some air bubbles and streaks where the
resin soaks into sanded areas of the veneer.  Wash/sand
off the amine blush and apply with a second coat of resin.

Wash/sand off the amine blush and sand the second coat 
being sure not to sand through to the veneer.  Remove 
the masking tape and fair out the edges that were masked off.

Detail of the sealed veneer.
The signs of a random orbital used at the factory.

Detail of some of the bigger cracks filled with resin and faired.

Finer resin filled cracks.

Paint the hull using acrylic primer and lightly sand.

Be sure to mask off the rails and deck to prevent
overspray contacting the deck.

Detail of the hull finish.

4 comments:

  1. painting a board interests me - only used primer or what was final coat ?? - thx

    ReplyDelete
  2. Yep, just primer. Sands nicely and adds minimal weight.

    ReplyDelete
  3. I like the fix! And real starboard grey ;).

    ReplyDelete
  4. very very nice all .
    and your photo i like it .

    ReplyDelete