Jump to content
Hand Crafted Angling

Bondo molds and bubbles

Recommended Posts

Posted back here a while ago about making some jig molds and what material out of. Decided on bondo as it seemed middle of the road on cost a durability. My plan is to make a mold of the mold on my 3d printer and cast that with bondo to make the jig mold. I did my first test run the other night. Mold was unusable anyway because I missed part of the mold box but I had an issue with air bubbles. There were holes in the finished mold right on the cavity of the jig. I’m not really sure how to eliminate them while pouring. I used bondo cut with fiberglass resin and Pam baking spray as a mold release. When I poured it I went slow and poured it in the empty space of the mold box. I didn’t really see many bubbles going in. Is there something I’m doing wrong?

Link to comment
Share on other sites

Start by pouring a stream as thin as possible about 8”-12” above the mold directly onto the master. Covering the master first with a thin coat will help almost eliminate air bubbles in your final product. Next fill the alignment holes.  Again thin stream. Then move to a corner and finish filling the mold allowing the bondo to flow across the mold. This should minimize the bigger bubbles. 
Holding the cup high and a thin stream allows the air bubbles a chance to burst. 

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...