I am making a sandwich design. I designed two parts that fit well together and assembled on Solidworks.

Top part: enter image description here

bottom part: enter image description here

The two parts are attached like two LEGO pieces. I want to pump water through one of the middle holes at the top part and exist through the other. My first plan is to glue the two-parts together. However, I feel that water will leak at the points where the two parts meet. Is there a smarter method in the 3D printing community ?


The seal you need will be pressure dependent. RTVs get great seals for the effort put into applications.

There are 'cement' glues designed for both pvc and abs (commonly used on pvc pipes) that work OK on sealing and bonding abs prints that fit inside one another.

2-part epoxies tend to do pretty well for most prints, but mixing and application can get messy and involved.

Whatever glue you use, be sure to account for it in your prints - glue takes space and sticks to rough surfaces well.


Without a seal or glue, you can't make two-object prints watertight.

face seal

A face seal is a compressible item that gets put under pressure and as a result, prevents the fluid from creeping through crevices. Rubber o-rings are a typical seal of this type, as are gaskets, but so is rubber (tube or string) in a dedicated indention or a gasket. Another type would be a Gland aka stuffing box or grease grove, which is then stuffed with a sealant - this could be string, hair, grease, or any type of other flexible material that reduces flow through by adhering to both sides and staying in the groove. With some designs, the gland can be packed with a fluid or viscous sealant after closing the item into its final position, for example by use of a syringe through a hole or a grease gun through a nipple.

Note that each of these designs has maximum pressures it can hold against.

enter image description here

Labyrinth Seal

A Labyrinth seal is a variant of a face seal, where two parts seal against one another by having many interlocking surfaces. A screw is pretty much a labyrinth seal. Most labyrinth seals are also packed with a sealant and, if around a spinning shaft, made from 2 halves that have a face seal against one another but only the (grease packed) labyrinth seal to the shaft.

Permanent sealant

A permanent sealant is a subtype of a sealant that can't be removed after installation. Some sealants in glands are permanent. The most common type of permanent sealant is glue. To pack them into the sealant gland from the outside, a syringe would be the best way. Depending on the pressure expected and the curing time of the sealant, just having a set of interlocking shallow grooves can be enough. Those then are coated before pressing the two halves together. The volume of the sealant needs to be taken into account in the design!


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.