Acrylic Crazing Bad?

[Mike Murphy]

I repaired a sump last night with some 2 part acrylic cement. I think I did not mix enough activator in the mix so it took longer to set but several areas even where I did not apply the cement crazed. It looks bad but I can't feel it on either side and it is on a sump anyway. Will it deteriorate further and leak?

The vapors were pretty strong so it must have been partially due to that in close proximity since there was areas of no contact that crazed.

Comments?

[MinibowMatt]

hmmm,. what brand cement?
Crazing isnt good in any event... it is stress fractures within the material caused by uneven pressures or solvent action (evaporating etc) im sure someone else can elaborate on this better.

I would be very concerned using a sump that was severly crazed, but that would depend on the location of the crazing too..

[stugray]

How long had the sump dried out before you glued it?

Acrylic absorbs a significant quantity of water during use.

If you attempt to glue it before the majority of the moisture has escaped, it crazes.

Stu

[Mike Murphy]

Dry for several days. Even areas that did not contact the cement crazed that were adjacent. Weld-On #40

[Acrylics]

The crazed areas were stressed, hence the crazing. Vapors from the resin or solvent can also craze highly stressed areas as well.
Would need to see pics to make any kind of judgment call as to anything else.

HTH,
James

[Mike Murphy]

That makes sense. The crack I repaired originated from a drilled bulkhead opening toward the bottom. It was hit on the bottom edge and cracked through the acrylic from the bottome edge of the opening and down to the bottom panel. My repairs on the outside did not craze but the repairs on the inside did. I speculated that trapped vapors caused this since areas affected had no cement on them. My outside patch consists of two 1/4 inch thick pieces that are bonded on starting at the bottom of the side panel and completely cover the original drilled hole. The stress crazed cracks appear to radiate out from the hole that was drilled. None of the crazing can be felt inside or outside with the edge of a finger nail and since I am not drilling another hole there I'm going to treat it as a none issue especially with the re-inforcement of the repairs I made in that area.

If anyone wants photos email me with you address and I will send them as I can't post here.

Thanks

[hebygb]

It makes sense that the crazing was initiated from the hole that was drilled. Most of the time this is a phenomenon associated with a rough cut. Between two well prepared edges the solvent will run the seam using a capilary method. In that case the solvent melts the acrylic and joins the seam. If one or both edges is un finished and rough, the solvent will flow inwards, and rather than melting the edge will penetrate into the mass of acrylic, causing the fissures.

[Acrylics]

After looking at the pics, I personally would consider it toast :(