fu box cracks and splits

General Discussion
1

so I was setting some 10.5" FU boxes this afternoon.Ive done this many a time...two black, one white, all with the same resin. I did not kick it too fast. not too slow either. the resin never got hot. while i was pouring around the perimeter of the white box, I accidentally got a drop or two of resin in it. I came back later with some acetone to "fix" the problem and splashed a little bit in the bottom of the box to get the drops out. after everything had cured I noticed little splits and cracks in thebottom of the white box...I picked at them with a stir stick and it seems as though it is a thin layer of the box that peeled and split at the bottom. thankfully the white boxed board is for me and not a customer, but I'm just wondering if anyone else has done this. Am I an idiot? probably. where did I go wrong? acetone? if it is just a thin coating on the box that peeled and it won't leak then I'll leave it. If it is structurally damaged, I'll route it out and attempt round two.

I never wipe my boxes down with acetone before I set them. I normally just rough sand them  with 100 grit. This is why i don';t know if acetone is to blame(and me of course :)

thanks

2

are they hollow inside? can I save it, or should I just install another one?

thanks

3

I USED TO wipe down my Proboxes with acetone. It works great for etching the box for resin adhesion.

One time, I got some acetone IN one of the boxes and didn’t wipe it out right away.

A few minutes later when I went to clean it out, it had melted the plastic of the insert and the box.

Everything was welded together and I couldn’t pull the insert out.

Acetone is nasty stuff

4

thanks. yes, nasty. scraping out hardened drips of resin in the bottom of a box  is also nasty. I don't use probox, so I don't know if it is the same material, but mine cracked and split perpendicular to the stringer. I thought abo it and it either reacted with the plastic, or the slight warmth from kicking resin combined with the fridgid temp of acetone caused rapid temp changes and messed everything up...looks like this mistake migh cost me 8 bucks and an hour of time. learning from your mistakes is not always fun. bummer

5

the boxs themselves are 2 pieces that are bonded together 

 

6

no saving just remove and replace.  not hollow just to molded pieces bonded together

 

 

7

Sounds like a plan...will route and try again in the morn. If anyone has any info on why this happened I would really appreciate it. I am puzzled and don't want this to happen again in the future. thanks for the help and useful information

8

    Howzit pierpoint, It maybe that where the 2 pieces are joined may get weakened by the Acetone and then it cracks from stress. That may also be the problem with the FU boxes and keep the acetone out of the inside of the boxes or plugs since if resin gets on there it will adhere and not want to come out but if it has just the finish it came with,any resin shout pop off. Hope this helps somebody. Aloha,Kokua