The pictures show the laminate preparation.
In view of all defects mentioned above, I will use 162g/m² glass cloth. This will probably get sturdy in the defects coverage.
waiting complete dry off and ready to start !
btw : This morning I spread some water on the mold to remove the foam dust. I also used sanding paper on the wet surface to modify some parts and I found out that the surface was becoming very smooth and without chipping. Too late discovery !!!
ClaudioD
PS :
1st glass coat done, no regrets !!! was the right decision, tomorrow the 2nd half, perhaps ! World Cycling Championship permitting !
I observe from the reflective light that will be necessary some filler in the gardbord area
Thank you so much for taking the time to share your passion with us. This project seems a perfect time to ask you about two general and basic techniques that elude me:
How do you report/trace these horizontal lines on the hull. One way I guess is to place the hull leveled on a support and use a black marker strap horizontaly on a wood bloc of the proper height. But the waterline behind the keel seems impossible to trace like this.
When the hull is cured, how will you trim the excess fiberglass/epoxy to get a nice deck line edge (I am lacking the proper ship slang here). This may be trivial as everyone skip this part in their “Build log”, but I have no clue. Well… I have some clues but none seems perfect or easy. Please be as elaborate as you dare. I am sure I will not be the only one that will benefit here from your wisdom.
Your point 1) is correct
I do have a bloc sliding with a marker and of course the marking aft the keel is not evident but I do it by hand. See message 5 to observe the full assy drawing.
I did it with a laser pocket lamp. See pictures below
For the 2) is just a simple hand cutter . I do use the edge of the deck line as a support guide and sliding the cutter. Rather easy !
Cheers
ClaudioD
PS:
I toke the same laser lamp and made a tilted slot in foam bloc as such to direct the light more vertically, the result is very good. At each cm can be made a dot !
A hand cutter like a hobby knive or a hand Dremel? I have never manipulate a laminated scaled hull so maybe I am wrong to imagine it hard and thick as an electronic circuit board. Is it more like cutting a Javel bottle?
Wow, that thin! Now I get it. You may have removed my last mental block towards a first try on an IACC120 build. Merci Claudio, and sorry for hacking your thread like this.
You show in post #44 a Laser lamp showing the waterline.
The Laser is shown drawing the Horizontal parts of the waterline, which it will do.
But, the other Photos show the Laser aiming down at the waterline, with the Laser in that position, the Laser spot can be aimed at any part of the Stern of the boat and would not be a true waterline indication !.
Cover up the drawn waterline, and with the Laser as shown - - try again !!.
I have just done this and it does not work as you claim !.
Drawing the horizontal parts onto the Hull, the Laser is level, moving it nearer or further away from the Hull does not affect the drawn lines - - - but at the stern it just does not work.
Hi Kevin,
Tuiga hull is still there since 5 years now. Very sturdy and heavy but is not escluded that I will do something about in the next 5 years !!!
Actually I will try to finish the J-Class Enterprise and de 12metre American Eagle and compare them in the water.
The last picture is very interesting about the reciprocal size.
Still I believe that a Vintage model around 120-130cm could call more interests then the larger and beautiful models, because of space and economics.
I was also trying smaller ones around 80cm but they will be too low in the water and would represent some difficulties of various order.
As often told , even small waves are becoming an important parameter for the model design
1st sanding operation followed by filler for major defects.
As Dick told, the glass coverage before anything else was the best solution, the defects are minimised in size. More sanding to finish and then packing tape coverage for definitive Hull making . I hope that packing tape will adhere without problems !
The spray paint undercoat, via some microholes, managed to go through the laminate and in many places the foam started melting under the skin. In the pictures below are visibles the ‘moon craters’ and other type of surface defects.
Repair is mandatory by using a non agressive filler to be found yet and remake the work again !
This is what I call e very bad surface finish !!!
I’m start thinking that the use of foam in spite of the ‘pseudo’ economic aspect, is showing the weaknesses if care about “melting” is not taken.
With a wooden mold this problem would not had occurred, but now I’m here and I shall play the game up to the end !
Use waterbased “everything” if you can - glues for sections, spray/rattle cans for paint, epoxy for heavy duty fastening needs
Make sure plastic packaging tape is securly fastened to foam, and provide an “assured” overlap of tape strips so any non-waterbased paint, glue, etc. will not have access to foam.
You cannot use traditional bodyfillers for automotive use - they usually are polyester based resins and will attack the foam - although if you give foam 1-2 coats of “neat” epoxy, that may (???) provide a barrier coat to the polyesters. (TRY AT YOUR OWN RISK - I do not recomend)
If you coat the foam with epoxy/glass - any pin holes will still allow paint thinners to “attack” the foam.
Hi Dick,
the first 3 points are the ones I use myself.
The mistake is derived from point 4, why, instead of covering the foam plug with one layer of 162G/m² glass, I should had used 3 layers of 80g/m² glass.
In that way the pinholes would had been reduced to a minimum and perhaps not big enough to let the nebuliser products of the undercoat acrilic spray passing through.
Yesterday I went to my usual shop and the only filler found is the one used to repair scratches before applying paperwall.
This is what I will try to use. see image below
If I don’t succeed I will apply epoxy resin with a brush, as a barrier all over the defects areas , use the polyester filler and then sanding again. As a last resource will be another layer of 80g/m² glass.
Lesson learn :>>>>> : FOAM PLUGS SHALL BE COVERED WITH 3 LAYERS OF 80 g/m² GLASS/EPOXY in order to reduce the risk associated with pinholes and for sturdier suface
that will work for fairing too. Here (US) we call it wallboard compound, joint compound, drywall “mud”, etc. It dries pretty hard, shrinks a bit if applied too thick, and still sands easily with medium grit sandpaper. I think you will still need to seal it when done, as it will get thin when it gets wet again.
A “trick” - sand down as close as possible, then use a “DAMP” sponge (not dripping wet) and wipe over the spots - the damp sponge will help blend the edges of the patch with the rest of the hull. Good luck Dick
