Cracking in peanut butter

[78 Thompson]

I drilled all my holes in my transom oversized and filled them with my mixture of peanut butter, which was pretty runny. I later had to thicken it up to do the fillet on the transom boards. But now that it is hard I noticed some cracking in the resin filled holes. Is that normal to get cracking or is it because the mixture was so thin?

 

[JASinIL2006]

I think if it was runny, that would be a good bet as to why it cracked. Did you have that problem with the larger fillets?

 

[kcassells]

I drilled all my holes in my transom oversized and filled them with my mixture of peanut butter, which was pretty runny. I later had to thicken it up to do the fillet on the transom boards. But now that it is hard I noticed some cracking in the resin filled holes. Is that normal to get cracking or is it because the mixture was so thin?

Most times when it cracks or swells is because it was made too "hot" and a blob in a hole for filling in depth over heats. Probably wouldn't if a skim coat
type of fix. Thing is I can't tell by the picks if it swelled.

 

[78 Thompson]

I think if it was runny, that would be a good bet as to why it cracked. Did you have that problem with the larger fillets?

No I didn’t notice any cracking in the fillets.
I put a lot more cabosil in to do the fillets.
Does that keep the heat and shrinking down, with more cabosil in the mix?
Would you recommend drilling the holes back out, and start over with a thicker mix?

 

[kcassells]

You can do that and add less to fill and come back after cure and finish it/fill it again, its about the depth of the fill and the heat it generates.
Just make a slower mix.
I would grind out the cracks and refill.

 

[JASinIL2006]

You can do that and add less to fill and come back after cure and finish it/fill it again, its about the depth of the fill and the heat it generates.
Just make a slower mix.
I would grind out the cracks and refill.

This. More Cabosil, less MEKP.