Reinforcing a Bow

[ontherocks83]

Kstep thanks for the clarification. I had missed the part of how long the duration was which makes a lot more sense now. I was under the impression of it just being a few minutes.

[zeehag]

it is good to know you are not badly damaged...is a serious thing to have happen...
i had considered placing a stainless protector on my ericson, as that boat gets dinged in bow from mooring ball and anchor chain....but i deferred that... when you figure out your cure, please advise....

[Oregon Waterman]

Originally Posted by Stumble

When people like you will recognize what the manufacturers tell them about the properties of the products they sell. Polyester is still used because it is cheap, not because it is structurally superior. It looses strength while wet, is brittle, has poor bond strength, has a lower tensile strength, absorbs water, but it's cheap.

Polyester resin doesn't fully cure until the final layer is applied and protected from air (typically with wax) which is why there are special poly resins to act as the final layer for exacally this purpose. This allows you to do layups in stages, but once the final layer is cured you can no longer get a chemical bond to it.

Of course polyester will bond to cured polyester, but it will be a much weaker bond than if you used epoxy, and much weaker than the original hot bond was.

Hate to jump on the train here but you do not know of what you speak.
There is no 'special' poly for the sanding coat, merely added wax.
And any poly damage I have repaired has never had a problem sticking to itself.
Epoxy has delam issue's, even the very best has issue's sticking to itself (Resin Research, Greg wrote the book on these resins).

Source: Me, surfboard shaper/glasser for 35 years.

[KStepman]

Originally Posted by zeehag

it is good to know you are not badly damaged...is a serious thing to have happen...
i had considered placing a stainless protector on my ericson, as that boat gets dinged in bow from mooring ball and anchor chain....but i deferred that... when you figure out your cure, please advise....

I have eliminated laminating Kevlar, for many of the reasons indirectly noted here.
A 3/16" (2.2cm) SS plate 5 feet (1.5 meters) x 2 feet. (.61 meters) folded on a break press at the angle of my bow weighs 85 lbs. 1/4" (.635cm) 110 lbs.

PVC is too easily abraded and fractured.

I am looking into High Density Polyethylene (HDPE). In 1/4" (.635cm) thickness, weighs 10.8 lbs (4.9kg) and can be heated and bent to shape.

If my initial research bears fruit, I will probably opt for HDPE or similar plastic to be attached with adhesive. I am reluctant to use permanent screws or bolts because of the damage at those stress points that may result due to variation in expansion/contraction between the fiberglass hull and the HDPE protective plate over time, and the effect that a possible collision might have at those through points.

I will advise.