EPOXY OR FIBREGLASS RESIN

[gavinabrown]

I have a large crack in my kitchen benchtop and and one side of it tarted to rise. I've sanded it back so that it is even, and now I want to fill it with a resin. I've bought some fibreglass resin from the hardware, but now am hearing about epoxy resin, which many people use to fix such cracks. But I can't find any information on the difference between the two. What is the difference, and which one should I use?

[q9]

I don't know what you bought but...

Depending on application, fibreglass can be coupled with epoxy resins...but you are likely to have bought a peroxide catalysing resin.

most notable feature of peroxides is the tendancy to shrink a little. Probably not what you want for your application. Get a purpose designed epoxy and it will go a lot better.

[Robson Valley]

Araldite epoxies have slightly better dimensional stability than the methacrylates used in FG resins.
For countertop repairs, you have to first stop the delamination, the source of the failure, then repair the visible.

Given the original intended application, there's a greater variety of tints/colors for the FG resin.

[soundman]

what you have probably baught is polyester resin.

people do fill voids with it sucessfully but it does nt have the afinity with wood or the structrual strength that epoxy does...in particular marine epoxy ( west or boat coat).

the epoxies are far better for filling cracks and the like.

Now your problem...you have a crack forming and one edge of the crack is rising....HMMM..sounds like you have some sort of stability problem....maybet it is moisture related.

you realy need to address this stability issue before you go filling the crack.....no matter what you do if you do nt address this stability problem, the wood will continue to move and the crack will continue to develop.

cheers

[gavinabrown]

what you have probably baught is polyester resin.

people do fill voids with it sucessfully but it does nt have the afinity with wood or the structrual strength that epoxy does...in particular marine epoxy ( west or boat coat).

the epoxies are far better for filling cracks and the like.

Now your problem...you have a crack forming and one edge of the crack is rising....HMMM..sounds like you have some sort of stability problem....maybet it is moisture related.

you realy need to address this stability issue before you go filling the crack.....no matter what you do if you do nt address this stability problem, the wood will continue to move and the crack will continue to develop.

cheers

I'd agree that it is moisture related but it is a timber benchtop and it is very 'stable'. The spot gets no more moisture than any other. I suspect that it just wasn't filled properly enough in the past so moisture affected it more. Hopefully, if I do a better job this time (than the guy who charged me $600!) it will be fine.

Cheers.

[soundman]

Optomism, often does not pay in these things.

it is most likley that the crack or the strees that caused it was there all along, it just opened up as the timber dried or aged.

are you proposing to fill this crack in place or remove the bench top?

If you think the crack may be moisture related, you need to dry the timber...that takes time...lots of it.

you need to stabilise the piece first.

a picture would help.

cheers