What caused the exterior finish to crack ?

[davelanthier]

In the last 3 days , 3 w/c canoes , all different owners , all ok before winter , all wintered without heat , all located in Jasper [ Alberta , Canada ]. All the canoes have 2 to 6 year old canvas which was installed by different shops . The cracking and checking extends into the filler . Winter temp. went down to -30 C [ about 19 F ] but this is not unusual . Any ideas what caused this and can it be repaired ?

 

[dboles]

Sorry to say cant offer any ideas but it seems you have cornered the Canoe market in Jasper.Maybe its time to offer franchises (be nice if I remembered how to spell)

 

[davelanthier]

fOraM splchek neded

Well I now know that dboles is no help [ which is unusual] but if anyone has a cause or remedy for these folks it would be much appreciated .

 

[MikeCav]

Since they were all done by different shops, is it possible that:

a) They all bought filler from the same source and the filler is bad; or

b) They all make their own filler, but purchased an ingredient for the filler from the same source and that ingredient was flawed?

Since these boats were canvassed/filled so long ago, and we boat folk are such meticulious record keepers - it will be difficult to track this down.

From what I understand from other and previous posts, there is no quick fix to cracked filler - recanvassing is about the best option.

 

[Martin Dumas]

Maybe they had an unusual weather occurence in Jasper this winter - a rapid and extreme shift of relative humidity or something like that. Just a thought...

Martin

 

[mark wismer]

Problem is the filler may continue to flake off. I had sections of paint that lifted down to th canvas weave. I filled them w/ acrylic spot & glazing compound a 3m product from auto body supply stores. It's designed to be applied over bondo and sanded smoothe & thin. It's lighter than bondo and has held tight for 5 years now.

These spots were tiny cracks that had been painted over several times. A few weeks in the warm sun lifted them all & I stored it in that condition for 15 years...they dated back to the summer camp that was the original owner. I applied the compound w/ plastic paddles like bondo and sanded 90% of it off. The paint adhered well and my bottom scratches alternate from grey filler to the pale blue/green compound. A light wet sanding was all I needed to recoat the bottom...

Sorry I can't determine the cause of your cracks. Looks like it's time to stock up on canvas & filler...

 

[davelanthier]

follow up

Jasper has a dry climate so it probably wasn't moisture caused . It is possible they might of had a quick change in temperature . On one of the canoes the outwale scarfing also separated .

 

[bob goeckel]

is it possible that the canoes were somewhat wet during an initial freeze and the expansion of ice crystals cracked the filler and the outwale scarf? i can see where moisture between the planking and canvas could be hidden and you not aware of it.

 

[davelanthier]

Bob ,I think you have the answer . If the canvas was still damp on the inside from use and then became frozen it seems reasonable that the filler /paint would crack . With the power of ice it wouldn't take much .

 

[bob goeckel]

do i win anything? i won a donut last week in the "roll up the rim to win contest" at tims. how can you beat that?

 

[davelanthier]

Problem solved ????

I have now just repaired 2 canoes where the filler and paint had cracked over winter due to freezing . The damaged areas were carefully power sanded with 100 grit then blown clean of dust . These areas were then well coated with West System G2 epoxy resin and allowed to set over night . The damaged areas were again power sanded with 100 grit , cleaned and a 2nd. coat of epoxy was applied . The entire canoe hull then received a final sanding and painting . I've been using one of the canoes , no problems and looks great . Best of all re-canvasing wasn't required .

 

[Ron Carter]

Sanded to what depth relative to the canvas?

I like the sound of your description but I'm having trouble visualizing how deep you sanded before the first coat of epoxy.

 

[davelanthier]

Hi Ron - I hope this makes sense . The paint and a small amount of filler [ not to the canvas ] were 1st. sanded . Keep in mind that the cracks were raised compared to the undamaged areas . The sanding was for good epoxy adhesion and cosmetics . The 1st. coat of epoxy soaked into and filled the cracks . The 2nd. coat of epoxy filled any final discrepancies to give a flat finish after it was sanded .

 

[Ron Carter]

Sanding

Understand now. Thanks for the quick reply.